new_contents: from __future__ import absolute_import
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import unittest
  from unittest import TestCase
  
  from spdx import config
  from spdx.version import Version
  
  class TestLicenseList(TestCase):
  
      def test_load_license_list(self):
          version, licenses_map = config.load_license_list(config._licenses)
          assert version == '2.6'
          # Test some instances in licenses_map
          assert licenses_map['MIT License'] == 'MIT'
          assert licenses_map['MIT'] == 'MIT License'
          assert licenses_map['Apache License 2.0'] == 'Apache-2.0'
          assert licenses_map['Apache-2.0'] == 'Apache License 2.0'
          assert licenses_map['GNU General Public License v3.0 only'] == 'GPL-3.0'
          assert licenses_map['GPL-3.0'] == 'GNU General Public License v3.0 only'
      
      def test_config_license_list_version_constant(self):
          assert config.LICENSE_LIST_VERSION == Version(major=2, minor=6)
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Add tests for config.py functions and constants.