(self, levels=1)
Push the current context of the given number of levels.

        Restrictions: after set-logic
Push the current context of the given number of levels.
Push the current context of the given number of levels .
def push(self, levels=1):
        """ Push the current context of the given number of levels.

        Restrictions: after set-logic
        """
        raise NotImplementedError
def push ( self , levels = 1 ) : raise NotImplementedError