@classmethod
def find_command(cls, verb):
    """Find a command in this shell's lineage by its verb.

        Will return the first command found, as multiple stores may have
        different commands using the same verb.

        :param str verb: The verb of the command to search for
        :returns Command|None: The command with that verb or None

        """
    verb = verb.lower()
    for shell in cls.get_lineage():
        command = shell.get_command(verb)
        if command:
            return command
