code: def date_to_json(value, obj):
      if value is None:
          return value
      else:
          # Dropping microseconds and only keeping milliseconds to conform
          # with JavaScript's Data.toJSON's behavior - and prevent bouncing
          # back updates from the front-end.
          return value.strftime("%Y-%m-%dT%H:%M:%S.%f")[:-3] + "Z"
  
imports: from traitlets import TraitError, TraitType
  import numpy
  import pandas
  import warnings
  import datetime
  import six
label_desc: Use image node_id 1 for calling a global function with example usage: date_to_json(value, obj) and returns: value, unknown