CheckMatrix = function (matrix)
{
    if (!Array.isArray(matrix) || !Array.isArray(matrix[0]))
    {
        return false;
    }

    //  How long is the first row?
    var size = matrix[0].length;

    //  Validate the rest of the rows are the same length
    for (var i = 1; i < matrix.length; i++)
    {
        if (matrix[i].length !== size)
        {
            return false;
        }
    }

    return true;
}
Checks if an array can be used as a matrix.

A matrix is a two-dimensional array (array of arrays), where all sub-arrays (rows)
have the same length. This is an example matrix:

```
[
   [ 1, 1, 1, 1, 1, 1 ],
   [ 2, 0, 0, 0, 0, 4 ],
   [ 2, 0, 1, 2, 0, 4 ],
   [ 2, 0, 3, 4, 0, 4 ],
   [ 2, 0, 0, 0, 0, 4 ],
   [ 3, 3, 3, 3, 3, 3 ]
]
```

@function Phaser.Utils.Array.Matrix.CheckMatrix
@since 3.0.0

@generic T
@genericUse {T[][]} - [matrix]

@param {T[][]} [matrix] - The array to check.

@return {boolean} `true` if the given `matrix` array is a valid matrix.