'Push the frame cf onto the stack. Return the new stack.'

def push(self, cf):

    cf.next = self
    if (self.state is not None):
        self.state.register_plugin('callstack', cf)
        self.state.history.recent_stack_actions.append(CallStackAction(hash(cf), len(cf), 'push', callframe=cf.copy(False)))
    return cf
