def signature(self, cmd):
        '''
        Convenience function that returns dict of function signature(s) specified by cmd.

        cmd is dict of the form:
        {
            'module' : 'modulestring',
            'tgt' : 'targetpatternstring',
            'tgt_type' : 'targetpatterntype',
            'token': 'salttokenstring',
            'username': 'usernamestring',
            'password': 'passwordstring',
            'eauth': 'eauthtypestring',
        }

        The cmd dict items are as follows:

        module: required. This is either a module or module function name for
            the specified client.
        tgt: Optional pattern string specifying the targeted minions when client
          is 'minion'
        tgt_type: Optional target pattern type string when client is 'minion'.
            Example: 'glob' defaults to 'glob' if missing
        token: the salt token. Either token: is required or the set of username:,
            password: , and eauth:
        username: the salt username. Required if token is missing.
        password: the user's password. Required if token is missing.
        eauth: the authentication type such as 'pam' or 'ldap'. Required if token is missing

        Adds client per the command.
        '''
        cmd['client'] = 'minion'
        if len(cmd['module'].split('.')) > 2 and cmd['module'].split('.')[0] in ['runner', 'wheel']:
            cmd['client'] = 'master'
        return self._signature(cmd)