layouts/a.grid.json

{
  "type": "grid",
  "data": {
    "columns": 24,
    "rowHeight": 20,
    "maxWidth": 1400,
    "bordered": true,
    "cells": [
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      },
      {
        "position": null
      }
    ]
  }
}