def addchild(self, child):
        """Add a new child to the command

        A child corresponds to a command located into a block (this
        command's block). It can be either an action or a control.

        :param child: the new child
        :return: True on succes, False otherwise
        """
        if not self.accept_children:
            return False
        self.children += [child]
        return True
Add a new child to the command

        A child corresponds to a command located into a block (this
        command's block). It can be either an action or a control.

        :param child: the new child
        :return: True on succes, False otherwise