code: def AddXrefTo(self, ref_kind, classobj, methodobj, offset):
          
          self.xrefto[classobj].add((ref_kind, methodobj, offset))
docs: Creates a crossreference to another class.
          XrefTo means, that the current class calls another class.
          The current class should also be contained in the another class' XrefFrom list.
  
          :param REF_TYPE ref_kind: type of call
          :param classobj: :class:`ClassAnalysis` object to link
          :param methodobj:
          :param offset: Offset in the Methods Bytecode, where the call happens
          :return: