'Create worksheet panes and mark them as split.
Args:
x:        The position for the vertical split.
y:        The position for the horizontal split.
top_row:  Topmost visible row in scrolling region of pane.
left_col: Leftmost visible row in scrolling region of pane.
Returns:
0:  Nothing.'

@convert_cell_args
def split_panes(self, x, y, top_row=None, left_col=None):

    self.freeze_panes(x, y, top_row, left_col, 2)
