code: def open_resource(self, plugin, filename):
          
          mod = self.load_plugin(plugin)
          fn = getattr(mod, '__file__', None)
          if fn is not None:
              if fn.endswith(('.pyc', '.pyo')):
                  fn = fn[:-1]
              if os.path.isfile(fn):
                  return open(os.path.join(os.path.dirname(fn), filename), 'rb')
          buf = pkgutil.get_data(self.mod.__name__ + '.' + plugin, filename)
          if buf is None:
              raise IOError(errno.ENOEXITS, 'Could not find resource')
          return NativeBytesIO(buf)
docs: This function locates a resource inside the plugin and returns
          a byte stream to the contents of it.  If the resource cannot be
          loaded an :exc:`IOError` will be raised.  Only plugins that are
          real Python packages can contain resources.  Plain old Python
          modules do not allow this for obvious reasons.
  
          .. versionadded:: 0.3
  
          :param plugin: the name of the plugin to open the resource of.
          :param filename: the name of the file within the plugin to open.