code: def _get_internal_field_by_name(self, name):
          
          field = self._all_fields.get(name, self._all_fields.get('%s.%s' % (self._full_name, name)))
          if field is not None:
              return field
          for field_name in self._all_fields:
              # Specific name
              if field_name.endswith('.%s' % name):
                  return self._all_fields[field_name]
docs: Gets the field by name, or None if not found.