class_docstr: python metrix unittest 
class_docstr_tok: ["python","metrix","unittest"]
docstr: test tooken error rate 
docstr_tok: ["test","tooken","error","rate"]
code: def test_token_err(self):
      """test tooken error rate"""
      config = utils.load_config(self.token_conf_file)
  
      metrics1 = metrics.get_metrics(
          config, y_true=self.token_true_label, y_pred=self.token_pred1
      )
      self.assertEqual(0.0, metrics1["TokenErrCal"])
  
      metrics2 = metrics.get_metrics(
          config, y_true=self.token_true_label, y_pred=self.token_pred2
      )
      self.assertEqual(0.75, metrics2["TokenErrCal"])
  
file_path: delta/delta/utils/metrics/py_metrics_test.py
imports: import os
  from pathlib import Path
  import tempfile
  import numpy
  import delta.compat
  from delta import utils
  from delta.utils import metrics
  from delta import PACKAGE_ROOT_DIR
label_desc: Use image node_id 4 for calling the MetricTest obj's underlying member method code with example usage: obj.test_token_err() without return types