getCellsAsGrid

Returns a list of all cells in this layer as a grid. The grid is a list of rows, where each row is a list of cells. The cells are ordered by their x and y coordinates.

For example, the first element of the returned list contains the first row of cells, the second element contains the second row of cells, and so on. Each row (which is also a list) contains the cells of that row, ordered by their x value.