_id
stringlengths
2
6
text
stringlengths
4
46k
title
stringclasses
1 value
d10201
because postsRepository is null, you need to initialized it final PostsRepository postsRepository = PostsRepository(); and remvoe it from constructor
d10202
Instead of using setBackgroundColor, you'll need to use setBackgroundDrawable, and use an xml state list drawable file with pressed/default states. http://developer.android.com/guide/topics/resources/drawable-resource.html#StateList
d10203
When you use setItem it overwrites the item which was there before it. You need to use getItem to retrieve the old list, append to it, then save it back to localStorage: function addEntry() { // Parse any JSON previously stored in allEntries var existingEntries = JSON.parse(localStorage.getItem("allEntries")); ...
d10204
defaultCenter will only be used by the map for the initial render, so it will not have any effect if you change this value later. If you use the center prop instead it will work as expected. const GoogleMapComponent = withScriptjs( withGoogleMap(props => ( <GoogleMap defaultZoom={13} center={props.map...
d10205
It appears that this is as designed. Click-once applications are designed to be deployed to one location. You can specify an update location, but these locations become static once the application is deployed. The best bet for anyone looking to do this would be some sort of content hosting solution ala Akamai. I tri...
d10206
You may try URL Rewrite if you're using IIS for hosting website.
d10207
use a closure to encapsulate the iterator at the time of adding into a local variable: for(var i=0;i<10;i++) { var el = new Element('div').inject($(document.root)); (function(i){ el.addEvent('click',function() { alert(i); }); }(i)); } school of thought says you should not c...
d10208
Just find select org.telegram.messenegr in spinner of Android Monitor section.
d10209
The reason is that indexing with one integer removes that axis: >>> X[:, 0].shape (180,) That's a one dimensional array, but if you index by giving a start and stop you keep the axis: >>> X[:, 0:1].shape (180, 1) which could be correctly appended to your array: >>> np.append(a, a[:, 0:1], 1) array([....]) But all th...
d10210
If your Linux system has the uncompress command, likely a script that runs gzip, then you can use that to decompress .Z files.
d10211
I would push all async tasks into a promise array and then return them all when all tasks complete: exports.markDevicesForDownload = functions.database.ref('/UserData/DeviceMgmt/Counters/NumberOfSelected').onUpdate((change) => { const changeRef = change.after.ref; const deviceMgmtRef = changeRef.parent.parent; // /...
d10212
You can use a PorterDuffColorFilter with a PorterDuff.Mode.SRC_IN. This example takes a Drawable and changes every non transparent pixel to green: drawable.setColorFilter(new PorterDuffColorFilter(Color.GREEN, PorterDuff.Mode.SRC_IN)); Note: You can easily apply it to a Bitmap converting it into a Drawable using Drawa...
d10213
I think you need to call your load mechanism again - since the datasource of your grid isn't updated so it will hold the old data from your last select. If you have performance issues loading the data again, you could manually alter the data of the edited row. A: quick fix: You can try to move this line to Page_Load()...
d10214
Plugins are generally not designed for use with a specific plugin manager. They all use more or less the same mechanisms and standardized file structure and should work the same way whether they are installed manually or "managed" with Vundle, Pathogen or some other script. You should read Vundle's and your non-working...
d10215
There are several ways to unit test HttpClient, but none are straightforward because HttpClient does not implement a straightforward abstraction. 1) Write an abstraction Here is a straightforward abstraction and you can use this instead of HttpClient. This is my recommended approach. You can inject this into your servi...
d10216
If you read Wiki you will see that it only removes duplicates at the same position, which is not the case here.
d10217
No there is no tool for this and this is in general a good thing when it comes to "complex" data in the graph. Spring Data Neo4j (6) does only fetch the relationships and properties of a node that you define in your model. If you would map your graph 1:1 you might end up with ones you do not need. They will pollute you...
d10218
No, I don't think this is natively supported by git. May be a local hook like a pre-commit one hook might try to check and checkout the right branch before allowing the commit to proceed.
d10219
Okay so the boto module goes through your boto configuration file to gather your credentials in order to create and edit data in the Google Cloud. If the boto module can not find the configuration file then you will get the errors above. What I did was since, after 3 days straight of trying to figure it out, I literall...
d10220
For building your application into a jar file, run mvn clean package which should create a target folder which contains the jar. Also, consider looking into the configuration for maven-jar-plugin maven-shade-plugin and maven-assembly-plugin to customize the jar more. For creating an installer for your application such ...
d10221
See this question Pass table as parameter to SQLCLR TV-UDF which has links to other related information. In short, TVP is not currently supported in SQL CLR. If the result set is small enough you could convert it to an XML type and pass that as a parameter to your SQL CLR function (SqlXml). You could also have the stor...
d10222
hg is the executable for Mercurial, you're going to need to download and install Mercurial. Once you have it installed you can use it to clone the project: hg clone https://xmppframework.googlecode.com/hg/ xmppframework
d10223
Wow wow, how tortured this is. def bugged_recursion(inp_value, list_index=0): # i don't get why you compare list_index here if list_index == 0: # you'll get an IndexError if list_index > len(inp_value) if inp_value[list_index] == 'valid': status = 'valid inp_value' else: ...
d10224
I'm guessing that the execution context under which your CGI is running is unable to complete the read() from the serial port. Incidentally the Python standard libraries have MUCH better ways for writing CGI scripts than what you're doing here; and even the basic string handling offers a better way to interpolate your ...
d10225
This isn't really an answer to the "why", but I managed to find out how to fix it myself: Instead of copying environmental variables from the current process, if I copy them with CreateEnvironmentBlock, then it works. I still haven't figured out what's causing it, though...
d10226
<my-component (click)="onClick()"></my-component> Case B: <my-component></my-component> Definition: @Component({ selector: 'my-component', templateUrl: './my-component.component.html', }) export class MyComponent { @???() hostHasClickListener: boolean; // I want to know this within my component } Thank you...
d10227
Add this statement on your header tag: <style> a:link{ text-decoration: none!important; cursor: pointer; } </style> A: a:link{ text-decoration: none!important; } => Working with me :) , good luck A: You have a block element (div) inside an inline element (a). This works in HTML 5, but not HTML 4. Thus also on...
d10228
Anonymous class new Something() {...} is not an instance of Something. Instead, it's a subclass/implementation of Something. And so, it's perfectly valid and useful to derive anonymous classes from interfaces. A: Anonymous class are not instance of a class but just another way to define a class, something similar to ...
d10229
If you run the same application on the same machine, with the same JVM, the heap and GC parameters will be the same. Ergonomics was a feature introduced way back in JDK 5.0 to try and take some of the guesswork out of GC tuning. A server-class machine (2 or more cores and 2 or more Gb of memory) will use 1/4 of phys...
d10230
There is an attribute in your AndroidManifest.xml file, like android:noHistory="true" You must delete this. it solves the problem A: Do like this private boolean isAddShown = false; make this isAddShown = true when the add is visible @Override public void onBackPressed() { // TODO Auto-generated method stub i...
d10231
Get LV group name for the item the mouse is down over: Private thisGroupName As String = "" Private Sub MouseDown(sender, e As MouseEventArgs)... If e.Button = MouseButtons.Right Then thisGroupName = GetLVGroupAt(e.X, e.Y) End If End Sub Private Function GetLVGroupAt(X As Integer, Y as Integer) As Str...
d10232
Answer Use the colorset argument of chart.CumReturns: plot_chart <- function(x, col) { ff <- tempfile() png(filename = ff) chart.CumReturns(x, colorset = col) dev.off() unlink(ff) } par(mar = c(2, 2, 1, 1)) plot_chart(xts1, col = plot_colors) addSeries(reclass(apply(xts1, 2, runSD), xts1)) par(mar = c(2, 2,...
d10233
You get the error for a very valid reason, that is not a valid jsonpath query. If you go to https://jsonpath.herokuapp.com/ ( which uses jayway ) and enter the same data and path you will see this is not a valid jsonpath query for jayway, or two of the other implementations, the only one that does not fail outright doe...
d10234
Most likely, your screenshot is of an ExpandableListView, or possibly a RecyclerView that uses a library to add expandable contents. A: Yes, and it's called Expandable List View.
d10235
Try this let path = GMSMutablePath() //Change coordinates path.add(CLLocationCoordinate2D(latitude: -33.85, longitude: 151.20)) path.add(CLLocationCoordinate2D(latitude: -33.70, longitude: 151.40)) path.add(CLLocationCoordinate2D(latitude: -33.73, longitude: 151.41)) let polyline = GMSPolyline(path: path) polyline.stro...
d10236
You can use the sed utility to parse out just the filenames sed 's_.*\/__' A: You can use awk: The easiest way that I find: awk -F/ '{print $NF}' file.txt or awk -F/ '{print $6}' file.txt You can also use sed: sed 's;.*/;;' file.txt You can use cut: cut -d'/' -f6 file.txt
d10237
There is a pretty simple fix. In your request-handling functions, where you would have: return Json(myStuff); Replace it with the overload that takes a JsonRequestBehavior: return Json(myStuff, JsonRequestBehavior.AllowGet);
d10238
SELECT A.AUCTION_ID FROM AUCTION_TABLE A EXCEPT SELECT B.AUCTION_ID FROM BIDS_TABLE B WHERE B.USER_ID='U1' Could you please try this
d10239
In Scala (and Java), reaching the eof means getting null when trying to read. I don't know how cin.bad translates, but it may be exceptions. Your example is equivalent to: def askUser( tries_left: Int = MAX_TRIES ):Int = Console.readLine match { case "^Z" | null => -9 case "?V" => { println( SSVID_ICO...
d10240
Your R2=0.909 is from the OLS on the train data, while the R2_score=0.68 is based on the correlation of the test data. Try predicting the train data and use R2_score on the train and predicted train data.
d10241
if you are working with blade, getting a working link this way is bad, you should use laravel helpers like the following: <form method="POST" action="{{route('site-subscriptions.store')}}" accept-charset="UTF-8" id="form_site_subscription_edit" enctype="multipart/form-data"> this way you are making sure that the links...
d10242
Yes, like so: public string Test { get; set; } public string AnotherTest { get { if(_anotherTest != null || Test == null) return _anotherTest; int indexLiteryS = Test.IndexOf("S") return Test.Substring(indexLiteryS, 4); } set { _anotherTest = value; } } private string _anotherTe...
d10243
You can try with : @GetMapping(value = '/limit') @ResponseBody public Limit limit() { return new Limit(1, 10000); } A: The following solved my problem: So yes, just to reiterate, going into my maven repo and deleting the fasterxml folder and re-running maven is what fixed the issue for me.
d10244
Look at @Owl 's answer, it fixes the other problems in your code too. In your loop the variable key is not defined. You'd have to write it like this: for (const key in this.colorValues) { ... } Although I wouldn't use a for-in loop, since objects have their own prototype properties, which you would also receive in a...
d10245
You can use a nested FOR JSON subquery, which breaks open the original JSON using OPENJSON and re-aggregates it SELECT p.ProductID, p.ProductName, ( SELECT p.ProductID, p.ProductName, j.Price, j.Shipper FROM OPENJSON(p.Results, '$.Results') WITH ( Pr...
d10246
You can use useState for that as well. Initialize randNum to '' and then, the place where you are console logging, set the value there. Inside the return function you can access the value by curly braces as {randNum} Including only relevant part of your code: function App() { const [randNum, setRandNumber] = useStat...
d10247
May be try to use http_s_:// when making api requests or opening the web-interface
d10248
You are binding your click events on document ready based on the value of selected - only the first click event in your code will ever be bound to the element as the initial value is zero. You need to move the logic in to the click function so that the value is checked every time the function runs: $(document).ready(fu...
d10249
You're busily waking up and going back to sleep at 100uS intervals -- 10 threads, 1ms, that's 100uS on average. And keep in mind that you have two context switches for each of those 100uS intervals, so you have a context switch every 50uS on average, or 20,000 times per second. Perhaps that's the answer you're looking...
d10250
If you're in a saga, simply yield the promise. Redux saga will wait for it to resolve and then resume the saga, much like await would do in an async function: const foo = () => Promise.resolve('foo'); const resultingPromise = foo(); function* exampleSaga() { const result = yield resultingPromise; console.log(resul...
d10251
Just #name would be enough to apply the style only to that specific element: #name { // your styles here } If you want to apply the style to all the elements using the class_name class, then you can use: .class_name { // your styles here } A: #name .class_name will apply to the children elements of your div wi...
d10252
Unless you have a lot of knowledge of how the compiler works, you cannot know a priori where these variables are stored, or even how they are represented. Each compiler designer makes his own rules for how/where variables are stored. You might be able to figure out for a specific compiled program, by inspecting the ge...
d10253
Try this: total=0 for i in range(5): num = int(input(f"Please enter number {i+1}: ")) total+=num print(total)
d10254
You can use NSPredicate to search the text inside your objects, like this let searchString = "test" var arr:NSArray = [["value" : "its a test text to find"], ["value" : "another text"], ["value" : "find this text"], ["value" : "lorem ipsum is a placeholder text commonly"], ["value" : "lorem ipsu...
d10255
The purpose of HWPF subproject is exactly that: process Word files. http://poi.apache.org/hwpf/index.html Then, to convert the data to XML you have to build XML by the ususal ways: StAX, JDOM, XStream... Apache offers a Quick Guide: http://poi.apache.org/hwpf/quick-guide.html and I also have found that: http://sanjaal....
d10256
This should work $('.quantity').click(function() { var that = this; $.post('quantity.php', { quantityId: $(that).attr('id') }, function(data) { $(that).html(data); }); }); But this is how i'd write it <div class="quantity" data-id='<?=$unique_id?>'> Quantity </div> $('.quantity').on...
d10257
The correct code: <form class="" action="insert.php" method="POST"> <input type="range" min="1" max="10" value="5" class="slider" id="myRange" name="myrange"> <p>Value: <span id="demo"></span></p> <button id="btn1">Click Here</button> </form> and in the insert.php: <?php $getRangeValue = $_POST['myrange']; $mys...
d10258
Using icmp package: const icmp = require('icmp'); icmp.send('8.8.8.8', "Hey, I'm sending a message!") .then(obj => { console.log(obj.open ? 'Done' : 'Failed') }) .catch(err => console.log(err)); A: if you use nodejs, you could use exec to call system ping command. const exec = require('child_proc...
d10259
I believe you need to add certificates information for envoy tls_context: common_tls_context: tls_certificates: - certificate_chain: filename: "/etc/ssl/certs/https.crt" private_key: filename: "/etc/ssl/certs/key.pem" And also add ...
d10260
I was passing the token wrong. Instead of: get '/me', params: {}, headers: {access_token: token.token} I had to use: get '/me', params: {}, headers: { 'Authorization': 'Bearer ' + token.token} A: You can check your Access Token factory's scopes, It should be same as initializer's default_scopes e.g. config/initializ...
d10261
You could do this a few different ways. What I would do is run one query that says "get me all pages ordered by the sum total of their items" then loop through them in php, and for each one, do a "get me the top 3 items for the current page". Make sense? Query one (untested, written on my phone): SELECT p.page_name, (S...
d10262
For reference, here's an example the doesn't have the problem. It uses a GridLayout(0, 1) with congruent gaps and border. Resize the enclosing frame to see the effect. Experiment with Box(BoxLayout.Y_AXIS) as an alternative. I suspect the original code (mis-)uses some combination of setXxxSize() or setBounds(), which w...
d10263
If you use ember-cli just create a file app/utils/area.js: export default function () {...}; and then you can import it and use it: import area from 'myapp/utils/area`; import Ember from 'ember'; export default Ember.Controller.extend({ area, }); However if you'r not using ember-cli, this question is not ember sp...
d10264
I think the only thing, you can do in your case, open all the values of a variable and select all and copy-paste like the Mark pointed out in his comment. A: Would a print statement work? you could use a global counter to keep track of which pass you are at and then compare the values in the consoles.
d10265
I would recommend you to use background tasks for that. Pausing your PHP script will not help you in speeding up page loading. Apache (or nginx or any other web-server) sends whole HTTP packet back to browser only when PHP script is completed. You can use some functions related to output stream and if web-server suppo...
d10266
Did it with. image = Image.open("./static/img/test.jpg") img_io = StringIO() image.save(img_io, 'JPEG', quality=70) img_io.seek(0) return send_file(img_io, mimetype='image/jpeg')
d10267
This should be: object[] attrs = type.GetCustomAttributes(true); Changing typeof(T) to input type. The GetCustomAttributes method gets attributes ON the called type. A: This line is the problem: object[] attrs = typeof(T).GetCustomAttributes(true); You're calling GetCustomAttributes on Type - not on the type that yo...
d10268
Exceptions thrown in tasks are always handled by the Task object itself. The exception is later rethrown when you, e.g., access the Task.Result property. This way the handling of the exception is left to the thread creating the Task. If you run the first code snippet and look at the Output pane, you'll see that there a...
d10269
I would suggest that rather than reload the entire root VC, you have separate data classes which you can reset as necessary - after all, the VC is really for displaying it all.
d10270
Use SimpleDateFormat: If your date is in 31/12/2014 format. String my_date = "31/12/2014" Then you need to convert it into SimpleDateFormat SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy"); Date strDate = sdf.parse(my_date); if (new Date().after(strDate)) { your_date_is_outdated = true; } else{ your_d...
d10271
you can add the title tag with JavaScript within your condition (if, else, or whatever) document.getElementById('myID').setAttribute('title', 'your tooltiptext'); dont Forget to set the id of your a-tag..
d10272
Using a session the way you suggested would screw up cases where (1) a visitor opens several different articles in multiple tabs, and (2) tries to write a reply on any tab other than the one that was opened last. The user might even write two replies simultaneously in different tabs; I sometimes do that on StackOverflo...
d10273
const arr = ["Foo", " ", "bar", " "]; var str = arr.join(" "); console.log('"' + str + '"'); console.log("str length: " + str.length); Works here... although you probably really meant to do arr.join(""); without the space.
d10274
Did the following, instead of WriteLinesToFile Task <SaveFormattedXml XmlString="%(ExportResult.FileContent)" FilePath="%(ExportResult.XmlFileName).xml"/> <UsingTask TaskName="SaveFormattedXml" TaskFactory="CodeTaskFactory" AssemblyFile="c:\Program Files (x86)\MSBuild\12.0\Bin\amd64\Microsoft.Build.Tasks.v12.0.dll"> <...
d10275
This is not valid SQL: CASE WHEN B1.BUSX != ' ' AND S1.S1TV = B1.BTX THEN 1 WHEN S1.S1TV = B1.B2TX THEN 1 ELSE 0 (although some databases do support it). Instead, use OR: ( (B1.BUSX <> ' ' AND S1.S1TV = B1.BTX) OR (B1.BUSX = ' ') ) I should point out that you can use CASE, but you ...
d10276
Since your token is somewhat dynamic, I would suggest that you shouldn't pass it directly to your view models. Rather, pass the AppState object and retrieve the token when needed. If you detect an expired token you can call a function on the AppState that obtains a refresh token and updates its token property.
d10277
In fact, in the case of a connection failure, the response object you receive in your error callback is an error one since the value of its type attribute is 3 (ERROR). What is a bit strange is that it seems that the preflighted request is executed and received a response. Could you give us its details from the Network...
d10278
I think it uses the .ashx to 1.) trigger the use of the ASP.NET isapi filter and 2.) signal that the requests aren't mapped to any physical files, but URLs mapped to logical pages within the Wiki engine. And I don't think it's dangerous to create ASP.NET page responses on the fly, which is essentially what they do. It'...
d10279
That's something you can fix with CSS. However, if you have a proper reference to the jQueryUI CSS file, I don't think you should be seeing this. Make sure that reference is present and correct.
d10280
<div> elements are set to span the width of their parent element, so changing the font size will have no effect on its actual width. Changing your <div> to a <span> should give you what you're looking for. A: Add float: left; to #holder #holder which is the test container for width, is defaulting to width: auto;. In...
d10281
Like everyone is pointing out making your own logging system is tricky. it required you to do additional steps to make the content secured. Not only to hackers but you as administrator of the database shouldn't have access to see your customers password in PlainText Most users will use the same password on your site as...
d10282
There's probably a more elegant way, but you could use a string template to represent the product/color combination. Playground Link interface Order { orderId: number; productName: string; color: string; quantity: number; price: number; link: string; } interface Summary { productNam...
d10283
There are two algorithms: restoring and non-restoring. This is very well described in Division Algorithms and Hardware Implementations by Sherif Galal and Dung Pham. And here is about implementation in VHDL.
d10284
The consumer test is analogous to a unit test. It will always pass if your code does what you expect it to in the test. It isn't dependent on prior state (such as a previous generated contract). The part of the process where you would check for a breaking change is in CI with the can I deploy tool (https://docs.pact.io...
d10285
pushAndRemoveUntil: Navigator.of(context).pushAndRemoveUntil(MaterialPageRoute(builder: (context) => LoginScreen()), (Route<dynamic> route) => false); This code will route to the login screen and pop all the screens which are in the back stack. popUntil: Navigator.of(context).popUntil(ModalRoute.withName('/widget_...
d10286
Try this code: $file_dir = "upload/demofiles"; if ($handle = opendir($file_dir)) { $i = 1; while (false !== ($entry = readdir($handle))) { $format = pathinfo($entry, PATHINFO_EXTENSION); $file_path = $file_dir.'/'.$entry; switch($format){ case "txt": $myfile = fopen($file_path, ...
d10287
It can be done with either html5 canvas or and old trick. If you want to "crop" irregular shapes, create an image and fill the irregular shape transparent and the rest same color as the background, then overlay the shape on top of the portion of the image you want to make irregular and if needed use a higher z-index. C...
d10288
Yes you would need to implement this using native code or thru the Socket API by implementing the DNS protocol calls. The InetAddress class can be used in the Android/Desktop ports but other platforms (e.g. iOS) would need the Objective-C/C equivalent of that.
d10289
The above code executes synchronously, therefore you return in the same frame before any promise has the chance to resolve. We can clean the above code up as follows: module.exports = app => { app.get("/api/seMapServerStatus", (req, res) => { const ports = ["27111", "27112", "27117", "27118", "27119", "27110", "...
d10290
VPC support has now been added for Elasticache in Cloudformation Templates. To launch a AWS::ElastiCache::CacheCluster in your VPC, create a AWS::ElastiCache::SubnetGroup that defines which subnet in your VPC you want Elasticache and assign it to the CacheSubnetGroupName property of AWS::ElastiCache::CacheCluster. A:...
d10291
To quote the documentation: The default character set and collation are latin1 and latin1_swedish_ci, so nonbinary string comparisons are case insensitive by default. This means that if you search with col_name LIKE 'a%', you get all column values that start with A or a. To make this search case sensitive, make sure t...
d10292
The number after image dimensions is supposed to be the maximum value in the image. You have it as '0'. Scanning quickly through the data, the value should be 247. Just replace the 0 with 247, using a text editor.
d10293
Here's what will happen when we run this: * *starting from the top, we define three different functions: clunk, thingamajig and display *then we initialize a variable called clunkCounter and assign to it the number 0 *then we call the thingamajig function, passing in the argument 5 for the size parameter *in th...
d10294
db.PersonDetails.aggregate([ {$lookup:{ from: "MotorDetails", localField:"personId", foreignField:"personIdEquivalentOnMotorDetails", as:"PersonToManufacturer" }} ]) Search on stackoverflow(check existing questions) and Google if you want to learn something new. Do not post direct questions where answers are...
d10295
I would change the colorList to array containing photoshop hex values and then use it like this: var nicEditorColorButton = nicEditorAdvancedButton.extend({ addPane : function() { var colorList = {0 : '000000',1 : 'FFFFFF'}; /* here goes color list */ var colorItems = new bkElement('DIV').setStyle({width: '270p...
d10296
There are two things to consider here. First, if you truly need a delay, it is better to await a promise than use sleep. You can do this via await new Promise (resolve => setTimeout(resolve, DELAY_LENGTH);. I use this frequently in conjunction with typing indicator to give the bot a more natural feeling conversation fl...
d10297
Fire event on button click like this $('.clickme').click(function(){ $('.nav-tabs > .active').next('li').find('a').trigger('click'); });
d10298
Test the type of the variable and branch the code. json_query filter helps to select the items from the list. Then ternary helps to conditionally select the value. The value of the first item that matches the condition is used. Defaults to 'NOTFOUND'. For example the play bellow for both versions of ou_reg_list - hosts...
d10299
For #2 you could access the sender "if the strategy is declared inside the supervising actor" If the strategy is declared inside the supervising actor (as opposed to within a companion object) its decider has access to all internal state of the actor in a thread-safe fashion, including obtaining a reference to the cur...
d10300
I'm afraid your code is invalid - the search algorithm requires forward iterators, but istreambuf_iterator is only an input iterator. Conceptually that makes sense - the algorithm needs to backtrack on a partial match, but the stream may not support backtracking. The actual behaviour is undefined - so the implementatio...