code: def _bind_field(self, field_name, field_obj):
          
          try:
              if field_name in self.load_only:
                  field_obj.load_only = True
              if field_name in self.dump_only:
                  field_obj.dump_only = True
              field_obj._bind_to_schema(field_name, self)
              self.on_bind_field(field_name, field_obj)
          except TypeError:
              # field declared as a class, not an instance
              if (isinstance(field_obj, type) and
                      issubclass(field_obj, base.FieldABC)):
                  msg = ('Field for "{}" must be declared as a '
                         'Field instance, not a class. '
                         'Did you mean "fields.{}()"?'
                         .format(field_name, field_obj.__name__))
                  raise TypeError(msg)
docs: Bind field to the schema, setting any necessary attributes on the
          field (e.g. parent and name).
  
          Also set field load_only and dump_only values if field_name was
          specified in ``class Meta``.