<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_arg_type_descriptors(self):
 """ The parameter type descriptor list for a method, or None for a field. Type descriptors are shorthand identifiers for the builtin java types. """


        if not self.is_method:
            return tuple()

        tp = _typeseq(self.get_descriptor())
        tp = _typeseq(tp[0][1:-1])

        return tp