old_contents: #-----------------------------------------------------------------------------
  # Copyright (c) 2012 - 2017, Anaconda, Inc. All rights reserved.
  #
  # Powered by the Bokeh Development Team.
  #
  # The full license is in the file LICENSE.txt, distributed with this software.
  #-----------------------------------------------------------------------------
  ''' Provide utility classes and functions useful for testing Bokeh itself.
  
  '''
  
  #-----------------------------------------------------------------------------
  # Boilerplate
  #-----------------------------------------------------------------------------
  from __future__ import absolute_import, division, print_function, unicode_literals
  
  import logging
  log = logging.getLogger(__name__)
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  
  # Standard library imports
  import importlib
  
  # External imports
  import pytest
  from six import string_types
  
  # Bokeh imports
  
  #-----------------------------------------------------------------------------
  # Globals and constants
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # General API
  #-----------------------------------------------------------------------------
  
  def verify_all(module, ALL):
      '''
  
      '''
      class Test___all__(object):
          def test___all__(self):
              if isinstance(module, string_types):
                  mod = importlib.import_module(module)
              else:
                  mod = module
              assert hasattr(mod, "__all__")
              assert mod.__all__ == ALL
  
          @pytest.mark.parametrize('name', ALL)
          @pytest.mark.unit
          def test_contents(self, name):
              if isinstance(module, string_types):
                  mod = importlib.import_module(module)
              else:
                  mod = module
              assert hasattr(mod, name)
      return Test___all__
  
  #-----------------------------------------------------------------------------
  # Dev API
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Private API
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Code
  #-----------------------------------------------------------------------------
  
new_contents: #-----------------------------------------------------------------------------
  # Copyright (c) 2012 - 2017, Anaconda, Inc. All rights reserved.
  #
  # Powered by the Bokeh Development Team.
  #
  # The full license is in the file LICENSE.txt, distributed with this software.
  #-----------------------------------------------------------------------------
  ''' Provide utility classes and functions useful for testing Bokeh itself.
  
  '''
  
  #-----------------------------------------------------------------------------
  # Boilerplate
  #-----------------------------------------------------------------------------
  from __future__ import absolute_import, division, print_function, unicode_literals
  
  import logging
  log = logging.getLogger(__name__)
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  
  # Standard library imports
  import importlib
  
  # External imports
  import pytest
  from six import string_types
  
  # Bokeh imports
  
  #-----------------------------------------------------------------------------
  # Globals and constants
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # General API
  #-----------------------------------------------------------------------------
  
  def verify_all(module, ALL):
      '''
  
      '''
      class Test___all__(object):
          def test___all__(self):
              if isinstance(module, string_types):
                  mod = importlib.import_module(module)
              else:
                  mod = module
              assert hasattr(mod, "__all__")
              assert mod.__all__ == ALL, "for module %s, expected: %r, actual: %r" % (mod.__name__, set(ALL)-set(mod.__all__), set(mod.__all__)-set(ALL))
  
          @pytest.mark.parametrize('name', ALL)
          @pytest.mark.unit
          def test_contents(self, name):
              if isinstance(module, string_types):
                  mod = importlib.import_module(module)
              else:
                  mod = module
              assert hasattr(mod, name)
      return Test___all__
  
  #-----------------------------------------------------------------------------
  # Dev API
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Private API
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Code
  #-----------------------------------------------------------------------------
  
subject: improve verify_all fail message (#8303)