code: def __init__(self, timestamp: datetime = None):
      self._timestamp = timestamp
  
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 1 to create a new NyokaSerializer object from inherited base classes: AbstractSerializer with example: obj = NyokaSerializer(timestamp)