code: def get_method(self, name, descriptor):
          
          key = name + str(descriptor)
          if key not in self.methods:
              self.methods[key] = ExternalMethod(self.name, name, descriptor)
  
          return self.methods[key]
docs: Get the method by name and descriptor,
          or create a new one if the requested method does not exists.
  
          :param name: method name
          :param descriptor: method descriptor, for example `'(I)V'`
          :return: :class:`ExternalMethod`