<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def listIds(self, exclude=list()):
 """ For each signer in this wallet, return its alias if present else return its identifier. :param exclude: :return: List of identifiers/aliases. """

        lst = list(self.aliasesToIds.keys())
        others = set(self.idsToSigners.keys()) - \
            set(self.aliasesToIds.values())
        lst.extend(list(others))
        for x in exclude:
            lst.remove(x)
        return lst