:param window1: The left pane.
:param window2: The right pane.
:param sashPosition: The initial position of the sash. If this
value is positive, it specifies the size of the left
:param window1: The left pane.
:param window2: The right pane.
:param sashPosition: The initial position of the sash. If this
value is positive, it specifies the size of the left