Return the bounding box, in pixels, of a region of the grid laid out in this container, as a 4-tuple (xoffset, yoffset, width, height). With no arguments the bounding box of the whole grid is returned. If column and row are given, the box spans from the cell at row and column 0 to that cell; if col2 and row2 are also given, it spans from the cell (column, row) to the cell (col2, row2).