code: def test_to_and_from_json_booleans(self):
      # training data
      d = {"col1": [True, False, True]}
      df = pd.DataFrame(data=d)
      # fit encoder
      le = LabelEncoder()
      le.fit(df["col1"])
  
      # new encoder
      new_le = LabelEncoder()
      new_le.from_json(json.loads(json.dumps(le.to_json(), indent=4)))
  
      # test data
      d_test = {"col2": [True, False, True]}
      df_test = pd.DataFrame(data=d_test)
      # transform
      y = new_le.transform(df_test["col2"])
  
      self.assertEqual(y[0], 1)
      self.assertEqual(y[1], 0)
      self.assertEqual(y[2], 1)
  
file_path: mljar-supervised/tests/tests_preprocessing/test_label_encoder.py
imports: import unittest
  import tempfile
  import json
  import numpy
  import pandas
  from supervised.preprocessing.label_encoder import LabelEncoder
label_desc: Use image node_id 5 for calling the LabelEncoderTest obj's underlying member method code with example usage: obj.test_to_and_from_json_booleans() without return types