docs: def version_range(guid, version, before=None, app_versions=None):
      """Returns all values after (and including) `version` for the app `guid`"""
  
      if app_versions is None:
          app_versions = validator.constants.APPROVED_APPLICATIONS
      app_key = None
  
      # Support for shorthand instead of full GUIDs.
      for app_guid, app_name in APPLICATIONS.items():
          if app_name == guid:
              guid = app_guid
              break
  
      for key in app_versions.keys():
          if app_versions[key]['guid'] == guid:
              app_key = key
              break
  
      if not app_key or version not in app_versions[app_key]['versions']:
          raise Exception('Bad GUID or version provided for version range: %s'
                          % version)
  
      all_versions = app_versions[app_key]['versions']
      version_pos = all_versions.index(version)
      before_pos = None
      if before is not None and before in all_versions:
          before_pos = all_versions.index(before)
  
      return all_versions[version_pos:before_pos]