def create_shape(self):
        """ Create the toolkit shape for the proxy object.

        This method is called during the top-down pass, just before the
        'init_shape()' method is called. This method should create the
        toolkit widget and assign it to the 'widget' attribute.

        """
        d = self.declaration
        if d.shape1 and d.shape2:
            self.shape = self._do_operation(d.shape1, d.shape2)
        else:
            self.shape = None
Create the toolkit shape for the proxy object.

        This method is called during the top-down pass, just before the
        'init_shape()' method is called. This method should create the
        toolkit widget and assign it to the 'widget' attribute.