'Add a child widget to the panedwindow in a new pane.
The child argument is the name of the child widget
followed by pairs of arguments that specify how to
manage the windows. The possible options and values
are the ones accepted by the paneconfigure method.'

def add(self, child, **kw):

    self.tk.call(((self._w, 'add', child) + self._options(kw)))
