class_docstr: Test Trial object and class.
docstr: Check property `Trial.duration` with no end time
docstr_tok: ["Check","property","`","Trial.duration","`","with","no","end","time"]
code: def test_duration_property_no_end_time(
      self, trial_config_no_end_time
  ):
      """Check property `Trial.duration` with no end time"""
      t = Trial(**trial_config_no_end_time)
      assert t.end_time is None
      assert t.heartbeat is not None
      assert t.duration == t.heartbeat - t.start_time
  
imports: import copy
  import datetime
  import os
  import warnings
  import bson
  import numpy
  import pytest
  from orion.core.worker.trial import Trial
label_desc: Use image node_id 39 for calling the TestTrial obj's underlying member method code with example usage: obj.test_duration_property_no_end_time(trial_config_no_end_time) without return types