'This method serves as a hook for other logic parsers that
have different boolean operators'

def get_BooleanExpression_factory(self, tok):

    if (tok in Tokens.AND_LIST):
        return AndExpression
    elif (tok in Tokens.OR_LIST):
        return OrExpression
    elif (tok in Tokens.IMP_LIST):
        return ImpExpression
    elif (tok in Tokens.IFF_LIST):
        return IffExpression
    else:
        return None
