docstr: The basename of the media's filepath.
code: def filename(self):
      """The basename of the media's filepath."""
      return os.path.basename(self.filepath)
  
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 8 for calling the _SampleMixin obj's underlying member method code with example usage: obj.filename() and returns: os