code: def _nyoka_data_field(
      self, data_field: models.DataField
  ) -> nyoka_pmml.DataField:
      return nyoka_pmml.DataField(
          name=data_field.name,
          optype=data_field.optype.name,
          dataType=data_field.dataType.name,
          Value=None
          if not data_field.values
          else [
              nyoka_pmml.Value(
                  value=val.value, property=val.property.name
              )
              for val in data_field.values
          ],
      )
  
imports: import typing
  import datetime
  import io
  import nyoka.PMML44
  import nyoka.base.constants
  from .abstract_serializer import AbstractSerializer
  from ..None import __version__
  from ..None import models
label_desc: Use image node_id 5 for calling the NyokaSerializer obj's underlying member method code with example usage: obj._nyoka_data_field(data_field) and returns: nyoka_pmml