text: class ConfigIncluderFile(object):
      """
       * Implement this <em>in addition to</em> {@link ConfigIncluder} if you want to
       * support inclusion of files with the {@code include file("filename")} syntax.
       * If you do not implement this but do implement {@link ConfigIncluder},
       * attempts to load files will use the default includer.
      """
  
      def include_file(self, context, what):
          """
          ConfigObject includeFile(ConfigIncludeContext context, File what);
  
           * Parses another item to be included. The returned object typically would
           * not have substitutions resolved. You can throw a ConfigException here to
           * abort parsing, or return an empty object, but may not return null.
           *
           * @param context
           *            some info about the include context
           * @param what
           *            the include statement's argument
           * @return a non-null ConfigObject
          """
          raise NotImplementedError
  