code: def test_CloneWithoutMetrics(self) -> None:
      data = Data(df=self.df)
      expected = Data(
          df=pd.DataFrame(
              [
                  {
                      "arm_name": "0_0",
                      "mean": 1.8,
                      "sem": 0.3,
                      "trial_index": 1,
                      "metric_name": "b",
                      "start_time": "2018-01-01",
                      "end_time": "2018-01-02",
                  },
                  {
                      "arm_name": "0_1",
                      "mean": 3.7,
                      "sem": 0.5,
                      "trial_index": 1,
                      "metric_name": "b",
                      "start_time": "2018-01-01",
                      "end_time": "2018-01-02",
                  },
                  {
                      "arm_name": "0_2",
                      "mean": 3.0,
                      "sem": None,
                      "trial_index": 1,
                      "metric_name": "b",
                      "start_time": "2018-01-01",
                      "end_time": "2018-01-02",
                  },
              ]
          )
      )
      self.assertEqual(clone_without_metrics(data, {"a"}), expected)
  
imports: import random
  import pandas
  from ax.core.data import clone_without_metrics, custom_data_class, Data, set_single_trial
  from ax.utils.common.testutils import TestCase
  from ax.utils.common.timeutils import current_timestamp_in_millis
label_desc: Use image node_id 10 for calling the DataTest obj's underlying member method code with example usage: obj.test_CloneWithoutMetrics() without return types