def __init__(self, default_cell_size=None):
super().__init__()<EOL>self._children = []<EOL>self._children_can_overlap = False<EOL>self._sizes = {}<EOL>self._grid = drawing.Grid()<EOL>self.cell_padding = first_not_none((<EOL>self.custom_cell_padding, self.custom_padding, <NUM_LIT:0>))<EOL>self.cell_alignment = self.custom_cell_alignment<EOL>self.default_cell_size = first_not_none((<EOL>default_cell_size, self.custom_default_cell_size))<EOL>
Initialize the container.

See `add()` for more details about the `default_cell_size` argument.