code: def test_empty_checkpoint_from_pb():
      chk_pb = empty_checkpoint_pb()
      expected = empty_checkpoint()
      assert pb_convert.checkpoint_from_pb(None, chk_pb) == expected
  
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 10 for calling a global function with example usage: test_empty_checkpoint_from_pb() without return types