File size: 25,931 Bytes

07c2d26

1
00:00:06,000 --> 00:00:06,000
Hello, Jim.

2
00:00:06,000 --> 00:00:12,000
Today we're going to learn with you what annotations are, how to work with them and how to create new

3
00:00:12,000 --> 00:00:12,000
ones.

4
00:00:12,000 --> 00:00:18,000
Before we start this lesson, I must say that it is critically important you watching previous lesson

5
00:00:18,000 --> 00:00:20,000
about Reflection API.

6
00:00:20,000 --> 00:00:26,000
If you skip that one, please make sure you watch it, because in this lesson, we are going to use

7
00:00:26,000 --> 00:00:29,000
Réflexion API to work with annotations.

8
00:00:29,000 --> 00:00:35,000
Basically, there is not so much as a ways for us to take advantage from annotations without knowing

9
00:00:35,000 --> 00:00:36,000
the Reflection API.

10
00:00:37,000 --> 00:00:39,000
In this lesson, we're going to learn everything.

11
00:00:39,000 --> 00:00:45,000
The related to annotations will start from the definition of annotation, make you understand what annotations

12
00:00:45,000 --> 00:00:47,000
are on the standard banner.

13
00:00:47,000 --> 00:00:53,000
We are going to discuss use cases when annotations may be applied and for what purposes.

14
00:00:53,000 --> 00:00:57,000
After that, we will start reviewing of the source code examples.

15
00:00:57,000 --> 00:01:02,000
I will explain you what targets annotation is and what retention annotation is.

16
00:01:02,000 --> 00:01:09,000
We are going to create our own custom annotation and you are going to understand how to create it and

17
00:01:09,000 --> 00:01:09,000
process it.

18
00:01:10,000 --> 00:01:15,000
And at the end of the lesson, I will also explain you how to create repeatable annotations.

19
00:01:15,000 --> 00:01:16,000
Let's stop.

20
00:01:17,000 --> 00:01:20,000
And the first question that we have to answer sounds like this.

21
00:01:21,000 --> 00:01:22,000
What is annotation?

22
00:01:22,000 --> 00:01:27,000
Annotation as a form of metadata provides data about programs.

23
00:01:27,000 --> 00:01:30,000
It is not part of the program itself.

24
00:01:30,000 --> 00:01:35,000
Annotations have no direct effect on the operation of the court.

25
00:01:35,000 --> 00:01:38,000
They annotate the understands this definition.

26
00:01:39,000 --> 00:01:40,000
The know what is metadata.

27
00:01:41,000 --> 00:01:50,000
Metadata is a data that provides information about other data or similar data about data in program,

28
00:01:50,000 --> 00:01:57,000
and we can annotate types, colossus and interfaces, fields, masses, parameters, constructors,

29
00:01:57,000 --> 00:02:01,000
local variables, packages, modules and others.

30
00:02:01,000 --> 00:02:04,000
We can even annotate annotation itself.

31
00:02:05,000 --> 00:02:11,000
Basically, there might be cases when you need to provide more information about your code and use this

32
00:02:11,000 --> 00:02:18,000
information on different stages on the level of the source code during compilation and at this stage

33
00:02:18,000 --> 00:02:18,000
of the runtime.

34
00:02:19,000 --> 00:02:25,000
Late in the lesson we are going to learn this case are some examples I will show you where notation

35
00:02:25,000 --> 00:02:29,000
can be applied and how long it will be retained.

36
00:02:29,000 --> 00:02:36,000
You already understood what metadata is and what annotation is, but probably it is still not clear

37
00:02:36,000 --> 00:02:42,000
for you how this can be helpful and when we need to use annotations in which cases.

38
00:02:42,000 --> 00:02:45,000
The first one is information for the compiler.

39
00:02:46,000 --> 00:02:53,000
Annotations can be used by the compiler to detect errors or suppress warnings, for example, such popular

40
00:02:53,000 --> 00:02:54,000
annotation as override.

41
00:02:55,000 --> 00:03:02,000
I am sure you used it already is on purpose or it just added it instead of you overwrite annotation

42
00:03:02,000 --> 00:03:05,000
discarded by the compiler during the compilation.

43
00:03:05,000 --> 00:03:09,000
And there is a specific purpose of this net information.

44
00:03:09,000 --> 00:03:14,000
As you remember, annotation tells us that this method should override method from parent type.

45
00:03:15,000 --> 00:03:22,000
Thus, there are specific requirements to access modify which that matter signature and the list of

46
00:03:22,000 --> 00:03:23,000
potential exceptions.

47
00:03:23,000 --> 00:03:32,000
There is a logical place in juju that analyzes this matter information basically for all methods marked

48
00:03:32,000 --> 00:03:34,000
with overrides, this logic is applied.

49
00:03:35,000 --> 00:03:37,000
Compile time and deployment time.

50
00:03:37,000 --> 00:03:45,000
Processing software tools can process annotation information to generate code, XML files and so forth.

51
00:03:45,000 --> 00:03:51,000
For example, such book in the library and do as number in case you have never worked with.

52
00:03:51,000 --> 00:03:51,000
No.

53
00:03:52,000 --> 00:03:53,000
I will tell you about it.

54
00:03:53,000 --> 00:03:59,000
It generates getters and setters for you and also helps you with generating other things.

55
00:04:00,000 --> 00:04:05,000
This mechanism also built on top of annotations and reflection API.

56
00:04:05,000 --> 00:04:12,000
Basically, you can annotate type was information about methods if you need to be generated, for example.

57
00:04:12,000 --> 00:04:19,000
And when you compile your application and upload classes into Java, those masses that you want it to

58
00:04:19,000 --> 00:04:21,000
be generated are there on place.

59
00:04:22,000 --> 00:04:23,000
Is that clear?

60
00:04:24,000 --> 00:04:27,000
And that's a use case of using annotations is runtime processing.

61
00:04:28,000 --> 00:04:31,000
Some annotations are available to be excellent at runtime.

62
00:04:32,000 --> 00:04:35,000
You can set configuration to retain annotations.

63
00:04:35,000 --> 00:04:39,000
Zero zero runtime I will show you is this an example?

64
00:04:39,000 --> 00:04:41,000
But let's understand why do we need this?

65
00:04:42,000 --> 00:04:48,000
You may need to keep annotations during the runtime to build some logic around this meta information.

66
00:04:48,000 --> 00:04:50,000
You're in the program execution.

67
00:04:50,000 --> 00:04:53,000
Your homework will be related to this case.

68
00:04:53,000 --> 00:04:58,000
I believe that we have learned enough basics to start review and examples.

69
00:04:58,000 --> 00:05:02,000
Anyway, I will explain examples as we go and the true.

70
00:05:02,000 --> 00:05:08,000
Who believes that understanding of this topic will be easier with source code and the real good examples,

71
00:05:08,000 --> 00:05:14,000
rather than with slides for the sake of the demo and this lesson, I created a separate package and

72
00:05:14,000 --> 00:05:15,000
separate them a file.

73
00:05:16,000 --> 00:05:19,000
You can find them a file in annotations package.

74
00:05:20,000 --> 00:05:21,000
Let's start from basics.

75
00:05:22,000 --> 00:05:24,000
Let's discuss annotation format.

76
00:05:24,000 --> 00:05:29,000
Each annotation is started with at sign, followed by some meaningful name.

77
00:05:30,000 --> 00:05:36,000
Z Sign character indicates as a compiler that what follows is an annotation.

78
00:05:36,000 --> 00:05:41,000
The annotation can include elements which can be named and zem values.

79
00:05:41,000 --> 00:05:48,000
For those elements, elements may contain additional information like in this case, you can see that

80
00:05:48,000 --> 00:05:50,000
are used to suppress warnings.

81
00:05:50,000 --> 00:05:54,000
Annotation and element value has value types.

82
00:05:54,000 --> 00:06:01,000
This is basically for compiler to remove warnings for parameterized, at least in case I would Corman's

83
00:06:01,000 --> 00:06:02,000
this annotation.

84
00:06:02,000 --> 00:06:08,000
There will be warnings you as a compilation that I am using parameter types without parameter Ryzens.

85
00:06:09,000 --> 00:06:17,000
You see this OK and other possible syntax of the similar annotation in case there is only one element

86
00:06:17,000 --> 00:06:19,000
is declared inside the annotation.

87
00:06:20,000 --> 00:06:25,000
You can omit element key and just put value like in this example.

88
00:06:25,000 --> 00:06:32,000
It is also possible to use multiple annotations at once and from Java version eight zero even supports

89
00:06:32,000 --> 00:06:34,000
of repeatable annotations.

90
00:06:34,000 --> 00:06:40,000
As you can see in this example, a little bit later in our lesson, one will comp the creation of our

91
00:06:40,000 --> 00:06:41,000
custom annotations.

92
00:06:41,000 --> 00:06:44,000
I will explain you how to create repeatable annotations.

93
00:06:45,000 --> 00:06:47,000
Let's open the source code of any annotation.

94
00:06:48,000 --> 00:06:51,000
For example, let's look at suppress warnings annotation.

95
00:06:52,000 --> 00:06:55,000
As you can see, there is no end in logic and code here.

96
00:06:56,000 --> 00:07:00,000
There is no any algorithm or data processing or anything else.

97
00:07:01,000 --> 00:07:10,000
Some students ask me then how annotations work, how overwrite annotation works, and all this basically

98
00:07:10,000 --> 00:07:15,000
annotations are nothing more than just an information and what you can do.

99
00:07:15,000 --> 00:07:16,000
Learn this information.

100
00:07:17,000 --> 00:07:21,000
This is up to you, and this logic is programmed in a separate place.

101
00:07:21,000 --> 00:07:24,000
OK, that was annotations basics.

102
00:07:24,000 --> 00:07:29,000
Now, you know, at least on the high level, what annotations are us?

103
00:07:29,000 --> 00:07:33,000
Know known annotations deeper and to learn them better?

104
00:07:34,000 --> 00:07:36,000
Let's create our own annotation.

105
00:07:36,000 --> 00:07:44,000
If you are already familiar with G-Unit will implement our own kind of test annotation if you are not

106
00:07:44,000 --> 00:07:45,000
familiar with your units yet.

107
00:07:45,000 --> 00:07:46,000
Just a few words.

108
00:07:47,000 --> 00:07:49,000
G-Unit is a framework for unit testing.

109
00:07:50,000 --> 00:07:56,000
It provides a lot of different features and the Mournes impossibility to run specific methods separately

110
00:07:57,000 --> 00:07:59,000
to execute separate test cases.

111
00:07:59,000 --> 00:08:06,000
The purpose of that massive is to reproduce the state of the system as a specific moment of time, and

112
00:08:06,000 --> 00:08:08,000
the Cert is expected to be here.

113
00:08:09,000 --> 00:08:15,000
All examples will be stored under this package, so you will easily found them in attachments to this

114
00:08:15,000 --> 00:08:17,000
lesson in case you want to run examples on your computer.

115
00:08:18,000 --> 00:08:19,000
Let's start.

116
00:08:19,000 --> 00:08:21,000
I create test annotations.

117
00:08:21,000 --> 00:08:28,000
First, I declare annotation in a separate file, and you can see in this example that the use interface

118
00:08:28,000 --> 00:08:30,000
here was at sign.

119
00:08:31,000 --> 00:08:38,000
The second important step is to add matter annotations to specify the scope and the target of our custom

120
00:08:38,000 --> 00:08:38,000
annotation.

121
00:08:39,000 --> 00:08:43,000
I'm talking about annotations, zero retention and target.

122
00:08:44,000 --> 00:08:44,000
Let's run.

123
00:08:44,000 --> 00:08:45,000
What are they?

124
00:08:46,000 --> 00:08:48,000
So what do we need to target annotation for?

125
00:08:49,000 --> 00:08:54,000
This annotation indicates a context in which an annotation type is applicable.

126
00:08:55,000 --> 00:09:02,000
In simple words, where you can use the sanitation target, annotation can take array of any values

127
00:09:02,000 --> 00:09:04,000
of element type enum.

128
00:09:05,000 --> 00:09:08,000
So even in case you forgot where you can use annotations.

129
00:09:09,000 --> 00:09:16,000
Just open element type in them and you would find enum for each possible placement of your annotation.

130
00:09:16,000 --> 00:09:24,000
Even despite the fact is, a on annotation may take array of elements in our specific example, we would

131
00:09:24,000 --> 00:09:33,000
use only one in a message because in our specific business context, we don't want to allow our client

132
00:09:33,000 --> 00:09:37,000
use it in other places is an exhortation is retention.

133
00:09:38,000 --> 00:09:43,000
This information indicates how long annotations was annotated.

134
00:09:43,000 --> 00:09:45,000
Time are to be retained.

135
00:09:45,000 --> 00:09:49,000
That is exactly what we have discussed at the beginning of our lesson.

136
00:09:49,000 --> 00:09:56,000
When I explained that annotation may be used during Zabeel time by the compiler and discarded from the

137
00:09:56,000 --> 00:10:02,000
class on the glass level but discarded during the anthem, one class is uploaded in.

138
00:10:03,000 --> 00:10:11,000
And during runtime, this annotation can take any value of retention policy in them, even in case you

139
00:10:11,000 --> 00:10:17,000
forgot what's retention levels for annotations are, you always can open the source code of this in

140
00:10:17,000 --> 00:10:19,000
them and explore this.

141
00:10:19,000 --> 00:10:22,000
As I said, there's three possible options here.

142
00:10:22,000 --> 00:10:31,000
They are source Closs, and one time in our case, we use runtime retention policy because we need this

143
00:10:31,000 --> 00:10:33,000
annotation to be retained.

144
00:10:33,000 --> 00:10:34,000
That's a runtime.

145
00:10:34,000 --> 00:10:41,000
Now, at this time, to add custom elements, imagine that you want to specify expected exception in

146
00:10:41,000 --> 00:10:47,000
order we can test negative scenarios, for example, in case we expect exception to be thrown.

147
00:10:47,000 --> 00:10:49,000
But there was no any exception.

148
00:10:49,000 --> 00:10:58,000
Drone zones This particular test should be considered as field and the stanzas declare an element in

149
00:10:58,000 --> 00:10:58,000
annotation.

150
00:10:58,000 --> 00:11:02,000
We have to declare mass was the name of the element itself.

151
00:11:03,000 --> 00:11:06,000
Return type will be the type of the element.

152
00:11:06,000 --> 00:11:12,000
For example, in this specific case, we would like to specify loss of the expected exception.

153
00:11:12,000 --> 00:11:18,000
Thus, returns type for this message will be close when we declare this matter.

154
00:11:18,000 --> 00:11:24,000
We should remember important things, since this massive can throw an exception.

155
00:11:24,000 --> 00:11:27,000
There is a restriction on the return types.

156
00:11:28,000 --> 00:11:35,000
Basically, you can return on your primitives string class in them, annotations and arrays of these

157
00:11:35,000 --> 00:11:36,000
types.

158
00:11:36,000 --> 00:11:39,000
Also, this must has default value.

159
00:11:40,000 --> 00:11:46,000
For example, in this particular case, default exception, to be certain is of non plus.

160
00:11:46,000 --> 00:11:51,000
This is our custom clause that extends Roble and that basically is empty.

161
00:11:52,000 --> 00:11:56,000
This is needed because I can't have default no values.

162
00:11:56,000 --> 00:12:03,000
But in case I wouldn't specify, a default value client will be forced to parse the value for this element.

163
00:12:03,000 --> 00:12:07,000
But what clients should Boston in case there is no expected exception?

164
00:12:07,000 --> 00:12:10,000
That's why I have default non clause here.

165
00:12:11,000 --> 00:12:14,000
Similar example of default value in our other element.

166
00:12:15,000 --> 00:12:19,000
Each test can be named and default name is empty string.

167
00:12:19,000 --> 00:12:23,000
But the client of this code can pass any custom name.

168
00:12:23,000 --> 00:12:26,000
One of the restriction was regards the default value.

169
00:12:26,000 --> 00:12:27,000
It can't be null.

170
00:12:28,000 --> 00:12:29,000
Is that clear?

171
00:12:29,000 --> 00:12:32,000
We are done with annotation creation.

172
00:12:32,000 --> 00:12:34,000
Let's now understand how to use it.

173
00:12:35,000 --> 00:12:39,000
As you can notice, there is no logic defined in the annotation.

174
00:12:39,000 --> 00:12:46,000
That means that I should have some place where logic for annotation process is described in this particular

175
00:12:46,000 --> 00:12:47,000
example.

176
00:12:47,000 --> 00:12:53,000
It can be some tests around the class similar to the G unit, where we have separate runners that can

177
00:12:53,000 --> 00:12:55,000
execute my tests.

178
00:12:56,000 --> 00:12:58,000
I open tests around the class.

179
00:12:58,000 --> 00:13:01,000
It has run tests massive that takes class.

180
00:13:01,000 --> 00:13:05,000
It contains tests to run as mass argument.

181
00:13:05,000 --> 00:13:11,000
I use this reference to a class object to get the array of all masses.

182
00:13:11,000 --> 00:13:18,000
After that, I feel the masses to keep in-stream only masses that have test annotation.

183
00:13:18,000 --> 00:13:24,000
After that, I filter all static masses to keep only non static masses in the stream.

184
00:13:24,000 --> 00:13:28,000
And now I need to call test my asset on the object.

185
00:13:28,000 --> 00:13:31,000
I create new instance using test class.

186
00:13:32,000 --> 00:13:39,000
After that, I need to speak logic for annotations that have expected exception and those who don't.

187
00:13:39,000 --> 00:13:42,000
You remember that annotations results?

188
00:13:42,000 --> 00:13:47,000
Bits of fired by client exception still has exception was not by default.

189
00:13:48,000 --> 00:13:55,000
I use this information during implementation of my logic because in case I expect any exceptions specified

190
00:13:55,000 --> 00:14:02,000
by client other than default, I need to check that the expected exception has been thrown come back

191
00:14:02,000 --> 00:14:04,000
losses of exceptions thrown.

192
00:14:04,000 --> 00:14:06,000
Here is the logic for that.

193
00:14:07,000 --> 00:14:15,000
By the way, in a reflection API in case exception has been thrown on the invoked received in the invocation

194
00:14:15,000 --> 00:14:20,000
target exception that serves as a wrapper for a regional exception.

195
00:14:21,000 --> 00:14:29,000
That's why I need to get course massive here to get the reference to the exception that caused invocation

196
00:14:29,000 --> 00:14:34,000
target exception in case I don't expect exception to this rule.

197
00:14:34,000 --> 00:14:41,000
Massad just should be executed successfully, and I just invoke mass differently.

198
00:14:41,000 --> 00:14:47,000
This is not the full replica of test annotation from G-Unit, but we have a goal in this lesson not

199
00:14:47,000 --> 00:14:53,000
to run G-Unit, but to understand how to work with annotations and process zap.

200
00:14:54,000 --> 00:14:57,000
Now let me show you class with tests.

201
00:14:57,000 --> 00:15:00,000
I open the glass, such as code test samples.

202
00:15:01,000 --> 00:15:02,000
This class contains.

203
00:15:02,000 --> 00:15:05,000
Is different mascots that are marked with test annotation.

204
00:15:06,000 --> 00:15:09,000
Each test has name for the sake of the current demo.

205
00:15:09,000 --> 00:15:17,000
I have two test cases here mascots that is executed without exception and massive that throws exception

206
00:15:17,000 --> 00:15:18,000
of expected type.

207
00:15:19,000 --> 00:15:20,000
Nothing complex here.

208
00:15:21,000 --> 00:15:27,000
And now let's write a code that will use my test runner to run these test cases.

209
00:15:28,000 --> 00:15:32,000
I open another clause at the so-called test annotation demo.

210
00:15:33,000 --> 00:15:34,000
I read instance of test runner.

211
00:15:35,000 --> 00:15:44,000
I could run test method and the person's glass that contains my test cases that so let's run this program

212
00:15:44,000 --> 00:15:45,000
and console.

213
00:15:45,000 --> 00:15:53,000
You can see that test without exception has been passed because we received exception that we expect

214
00:15:53,000 --> 00:16:01,000
and test without exception also has been passed because it was executed without any exception.

215
00:16:02,000 --> 00:16:06,000
I recommend you to look through the source code that I left in attachments to the lesson.

216
00:16:06,000 --> 00:16:11,000
Run it on your local computer to understand better how it works.

217
00:16:12,000 --> 00:16:16,000
And the last thing for the desert I'd like to share with you is repeatable annotations.

218
00:16:17,000 --> 00:16:23,000
To be honest, in my opinion, this is a very rare case because in case you need to pass multiple values,

219
00:16:24,000 --> 00:16:30,000
you always can define additional elements in the original annotation or declare array of values for

220
00:16:30,000 --> 00:16:31,000
some element.

221
00:16:32,000 --> 00:16:39,000
Anyway, it was hard for me to come up with real life example in this case, but I just want to demonstrate

222
00:16:39,000 --> 00:16:42,000
use a feature that was added in Java version eight.

223
00:16:42,000 --> 00:16:44,000
Let me open our demo example.

224
00:16:45,000 --> 00:16:48,000
Can they see that I have Orser annotation here duplicated?

225
00:16:49,000 --> 00:16:56,000
Normally it is not accepted, and to be able to use the same annotation twice for the same element,

226
00:16:56,000 --> 00:16:59,000
you need to perform additional actions.

227
00:17:00,000 --> 00:17:07,000
The first thing to do is to add annotation, repeatable annotation definition, like I did for Orser

228
00:17:07,000 --> 00:17:08,000
annotation.

229
00:17:08,000 --> 00:17:15,000
The second thing to do is to create container for repeatable annotations for compatibility reasons.

230
00:17:15,000 --> 00:17:19,000
Repeating annotations are stored in a container annotation.

231
00:17:20,000 --> 00:17:25,000
In order for the compiler to do this, two declarations are required in your code.

232
00:17:25,000 --> 00:17:30,000
That's why another annotation that we need to create is here.

233
00:17:30,000 --> 00:17:39,000
I call it Auster's container annotation must have element value that returns array with objects of repeatable

234
00:17:39,000 --> 00:17:42,000
annotation type that we want to repeat.

235
00:17:42,000 --> 00:17:47,000
In this case, value element will contain array of Orser annotations.

236
00:17:47,000 --> 00:17:48,000
Is that clear?

237
00:17:49,000 --> 00:17:52,000
Basically, that's all what I wanted to share with you.

238
00:17:53,000 --> 00:17:55,000
Let's review what we have learned in this lesson.

239
00:17:56,000 --> 00:18:03,000
In this lesson, we have learned what annotation is also explained to you, why we might need an addition

240
00:18:03,000 --> 00:18:05,000
and when we can use it.

241
00:18:05,000 --> 00:18:08,000
Now, you know where annotations may be applied.

242
00:18:09,000 --> 00:18:13,000
You know why we need targeted annotation and you know what element type in them is.

243
00:18:14,000 --> 00:18:19,000
Also, you learned what retention annotation is and what retention policy in them is.

244
00:18:20,000 --> 00:18:21,000
In the lesson.

245
00:18:21,000 --> 00:18:27,000
We created our custom annotation, and at the end of the lesson, I explained to you how to create repeatable

246
00:18:27,000 --> 00:18:28,000
annotations.

247
00:18:29,000 --> 00:18:32,000
Basically, that's a summary of all what we have learned today.

248
00:18:32,000 --> 00:18:37,000
I have a homework for you in order you can practice in creation of annotations.

249
00:18:37,000 --> 00:18:41,000
You also can find a link to the whole in attachment to the lesson.

250
00:18:41,000 --> 00:18:44,000
Let's understand what you need to do in this task.

251
00:18:45,000 --> 00:18:49,000
You need to create to do annotation that will allow us to track the progress of note.

252
00:18:49,000 --> 00:18:50,000
Implement that message.

253
00:18:51,000 --> 00:18:57,000
To do annotation has different elements such as author, priority and stages.

254
00:18:57,000 --> 00:19:05,000
Some of them have default values and also Element doesn't have annotation can be applied only to masses

255
00:19:05,000 --> 00:19:07,000
and should be available under on that.

256
00:19:07,000 --> 00:19:14,000
We'll see to create separate classes at the school to do analyzer in that class, we should have massive

257
00:19:14,000 --> 00:19:22,000
three chance string value that is generated to do report pay attention that in order your homework would

258
00:19:22,000 --> 00:19:23,000
be considered to be done.

259
00:19:24,000 --> 00:19:28,000
You need to follow specific partners for each method analysis.

260
00:19:28,000 --> 00:19:30,000
One is described here.

261
00:19:30,000 --> 00:19:35,000
You should specify method name or search priority on stages.

262
00:19:35,000 --> 00:19:42,000
Is it clear any way you will be able to find my solution also in attachments does assessment, but try

263
00:19:42,000 --> 00:19:49,000
to solve this task without any help and by yourself first and only in case solution is not on this for

264
00:19:49,000 --> 00:19:49,000
you.

265
00:19:49,000 --> 00:19:56,000
Use my solution as a reference and as always, in case you have any questions, feel free to add your

266
00:19:56,000 --> 00:19:58,000
questions in comments on this video.

267
00:19:59,000 --> 00:20:01,000
Thanks a lot you for your attention.

268
00:20:01,000 --> 00:20:04,000
Have a great day and see in the next lesson.