code: def test_frame_metadata(self):
      df = pd.DataFrame(
          {"A": [1, 2, 3], "B": [4, 5, 6], "C": [7, 8, 9]},
          index=["a", "b", "c"],
          columns=["A", "B", "C"],
      )
      s = pd.Series([1, 2, 3], index=["a", "b", "c"])
      mdf = pdml.ModelFrame(df, target=s)
  
      self.assertEqual(mdf.target_name, ".target")
      sliced = mdf.iloc[1:2,]
      self.assertIsInstance(sliced, pdml.ModelFrame)
      self.assertTrue(sliced.has_target())
      self.assertEqual(sliced.target_name, ".target")
  
      df = pd.DataFrame(
          {"A": [1, 2, 3], "B": [4, 5, 6], "C": [7, 8, 9]},
          index=["a", "b", "c"],
          columns=["A", "B", "C"],
      )
      mdf = pdml.ModelFrame(df, target="A")
  
      self.assertEqual(mdf.target_name, "A")
      sliced = mdf.loc[["a", "b"], :]
      self.assertIsInstance(sliced, pdml.ModelFrame)
      self.assertTrue(sliced.has_target())
      self.assertEqual(sliced.target_name, "A")
  
      sliced = mdf.iloc[[1, 2], :]
      self.assertIsInstance(sliced, pdml.ModelFrame)
      self.assertTrue(sliced.has_target())
      self.assertEqual(sliced.target_name, "A")
  
imports: import pytest
  import datetime
  import warnings
  import numpy
  import pandas
  import sklearn.datasets
  import sklearn.svm
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 20 for calling the TestModelFrame obj's underlying member method code with example usage: obj.test_frame_metadata() without return types