code: def dataset_id(self):
      return self._doc._dataset_id
  
imports: import os
  from bson import ObjectId
  from fiftyone.core.document import Document, DocumentView
  import fiftyone.core.frame
  import fiftyone.core.frame_utils
  import fiftyone.core.labels
  import fiftyone.core.metadata
  import fiftyone.core.media
  import fiftyone.core.odm
  import fiftyone.core.utils
  from fiftyone.core.singletons import SampleSingleton
label_desc: Use image node_id 6 for calling the _SampleMixin obj's underlying member method code with example usage: obj.dataset_id() and returns: self