code: def get_serializer_info(self, serializer):
          
          if hasattr(serializer, 'child'):
              # If this is a `ListSerializer` then we want to examine the
              # underlying child serializer instance instead.
              serializer = serializer.child
          return self.get_fields(serializer.fields)
docs: Given an instance of a serializer, return a dictionary of metadata
          about its fields.