code: def empty_checkpoint():
      return Checkpoint(
          id="foo",
          created=datetime.datetime(2020, 12, 7, 1, 13, 29, 192682),
          step=0,
      )
  
imports: import datetime
  from keepsake import pb_convert
  from keepsake.checkpoint import Checkpoint, PrimaryMetric, CheckpointList
  from keepsake.experiment import Experiment
  from keepsake.servicepb import keepsake_pb2
  from keepsake.project import Project
label_desc: Use image node_id 4 for calling a global function with example usage: empty_checkpoint() and returns: Checkpoint