old_contents: # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright 2012 Nebula, Inc.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  """ The Horizon interface.
  
  Contains the core Horizon classes--:class:`~horizon.Dashboard` and
  :class:`horizon.Panel`--the dynamic URLconf for Horizon, and common interface
  methods like :func:`~horizon.register` and :func:`~horizon.unregister`.
  
  """
  # Because this module is compiled by setup.py before Django may be installed
  # in the environment we try importing Django and issue a warning but move on
  # should that fail.
  Horizon = None
  try:
      from horizon.base import Dashboard  # noqa
      from horizon.base import Horizon  # noqa
      from horizon.base import Panel  # noqa
      from horizon.base import PanelGroup  # noqa
  except ImportError:
      import warnings
  
      def simple_warn(message, category, filename, lineno, file=None, line=None):
          return '%s: %s' % (category.__name__, message)
  
      msg = ("Could not import Horizon dependencies. "
             "This is normal during installation.\n")
      warnings.formatwarning = simple_warn
      warnings.warn(msg, Warning)
  
  if Horizon:
      register = Horizon.register
      unregister = Horizon.unregister
      get_absolute_url = Horizon.get_absolute_url
      get_user_home = Horizon.get_user_home
      get_dashboard = Horizon.get_dashboard
      get_default_dashboard = Horizon.get_default_dashboard
      get_dashboards = Horizon.get_dashboards
      urls = Horizon._lazy_urls
  
  # silence flake8 about unused imports here:
  assert Dashboard
  assert Panel
  assert PanelGroup
  
new_contents: # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright 2012 Nebula, Inc.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  """ The Horizon interface.
  
  Contains the core Horizon classes--:class:`~horizon.Dashboard` and
  :class:`horizon.Panel`--the dynamic URLconf for Horizon, and common interface
  methods like :func:`~horizon.register` and :func:`~horizon.unregister`.
  
  """
  # Because this module is compiled by setup.py before Django may be installed
  # in the environment we try importing Django and issue a warning but move on
  # should that fail.
  Horizon = None
  try:
      from horizon.base import Dashboard  # noqa
      from horizon.base import Horizon  # noqa
      from horizon.base import Panel  # noqa
      from horizon.base import PanelGroup  # noqa
  except ImportError:
      import warnings
  
      def simple_warn(message, category, filename, lineno, file=None, line=None):
          return '%s: %s' % (category.__name__, message)
  
      msg = ("Could not import Horizon dependencies. "
             "This is normal during installation.\n")
      warnings.formatwarning = simple_warn
      warnings.warn(msg, Warning)
  
  if Horizon:
      register = Horizon.register
      unregister = Horizon.unregister
      get_absolute_url = Horizon.get_absolute_url
      get_user_home = Horizon.get_user_home
      get_dashboard = Horizon.get_dashboard
      get_default_dashboard = Horizon.get_default_dashboard
      get_dashboards = Horizon.get_dashboards
      urls = Horizon._lazy_urls
  
  # silence flake8 about unused imports here:
  __all__ = [
      "Dashboard",
      "Horizon",
      "Panel",
      "PanelGroup",
      "register",
      "unregister",
      "get_absolute_url",
      "get_user_home",
      "get_dashboard",
      "get_default_dashboard",
      "get_dashboards",
      "urls",
  ]
  
subject: Remove asserts for optional imports