code: def test_transform(self):
      d_test = {
          "col1": [1, 1, np.nan, 3],
          "col2": ["a", "a", np.nan, "a"],
          "col3": [1, 1, 1, 3],
          "col4": ["a", "a", "b", "c"],
          "y": [np.nan, 1, np.nan, 2],
      }
      df_test = pd.DataFrame(data=d_test)
      X = df_test.loc[:, ["col1", "col2", "col3", "col4"]]
      y = df_test.loc[:, "y"]
  
      self.assertEqual(X.shape[0], 4)
      self.assertEqual(y.shape[0], 4)
      X, y, _, _ = ExcludeRowsMissingTarget.transform(X, y)
      self.assertEqual(X.shape[0], 2)
      self.assertEqual(y.shape[0], 2)
  
      self.assertEqual(y[0], 1)
      self.assertEqual(y[1], 2)
  
file_path: mljar-supervised/tests/tests_preprocessing/test_exclude_missing.py
imports: import unittest
  import tempfile
  import numpy
  import pandas
  from supervised.preprocessing.exclude_missing_target import ExcludeRowsMissingTarget
label_desc: Use image node_id 1 for calling the ExcludeRowsMissingTargetTest obj's underlying member method code with example usage: obj.test_transform() without return types