def METHOD_NAME(self, resolverClass, serials=None):
    """
    get the tokens of the src resolver
    :param resolverClass: the resolver class defintions as in the tokendb
    :param serials: the set of serials, which should be worked out
                    - if None, all tokens of the resolvers are searched
    """
    rcondition = and_(Token.LinOtpIdResClass.like(resolverClass))
    scondition = None
    if serials:
        # filter token serials
        serials = ",".join(serials.split(","))
        scondition = and_(Token.LinOtpTokenSerialnumber.in_(serials))
    #  create the final condition as AND of all conditions
    condTuple = ()
    for conn in (scondition, rcondition):
        if type(conn).__name__ != "NoneType":
            condTuple += (conn,)
    tokens = Token.query.filter(*condTuple).all()
    return tokens