code: def warn_if_fields_defined_in_meta(fields, Meta):
      
      if getattr(Meta, "fields", None) or getattr(Meta, "additional", None):
          declared_fields = set(fields.keys())
          if (
              set(getattr(Meta, "fields", set())) > declared_fields
              or set(getattr(Meta, "additional", set())) > declared_fields
          ):
              warnings.warn(
                  "Only explicitly-declared fields will be included in the Schema Object. "
                  "Fields defined in Meta.fields or Meta.additional are ignored."
              )
docs: Warns user that fields defined in Meta.fields or Meta.additional will
      be ignored
  
      :param dict fields: A dictionary of fields name field object pairs
      :param Meta: the schema's Meta class