@classmethod<EOL><INDENT>def get_action(cls, alias):<DEDENT>
for action, alias_list in cls.action_map.items():<EOL><INDENT>if alias in alias_list:<EOL><INDENT>return action<EOL><DEDENT><DEDENT>return None<EOL>
Find the name of the action for the supplied alias.  If no action is
        asociated with the given alias, None is returned.

        :param alias: the alias to look up
        :type alias: str
        :rturns: the name of the corresponding action or None
        :rtype: str or NoneType