new_contents: # -*- coding: utf-8 -*-
  """Testing CLI module
  
  Only supports Python 3.x now"""
  
  import unittest
  
  # Resolve import problem
  import os
  os.chdir("../")
  
  from vocabtool import core
  
  
  class TestCoreConfig(unittest.TestCase):
      """Test case for the config components of core"""
  
      def setUp(self):
          pass
  
      def tearDown(self):
          pass
  
      def test_load_config(self):
          pass
  
      def test_read_config(self):
          pass
  
      def test_write_config(self):
          pass
  
  
  class TestCoreLookUp(unittest.TestCase):
      """Test case for core's components related to looking up words"""
  
      def setUp(self):
          pass
  
      def tearDown(self):
          pass
  
      def test_lookup_invalid_word(self):
          pass
  
      def test_lookup_invalid_language(self):
          pass
  
      def test_lookup_empty_source_list(self):
          pass
  
  
  class TestCoreAddToDatabase(unittest.TestCase):
      """Test case for core's components related to adding entries to database"""
  
      def setUp(self):
          pass
  
      def tearDown(self):
          pass
  
      def test_add_to_database(self):
          pass
  
  
  class TestCoreGenerateLaTeX(unittest.TestCase):
      """Test case for core's components related to generate LaTeX output"""
  
      def setUp(self):
          pass
  
      def tearDown(self):
          pass
  
      def test_generate(self):
          pass
  
  if __name__ == "__main__":
      unittest.main()
  
subject: Add preliminary test suite for core.py