docs: def bind_to_env(self, bound_env):
          '''
          Get a copy of the reverse, bound to `env` object.
          Can be found in env.root attribute::
  
              # done in iktomi.web.app.Application
              env.root = Reverse.from_handler(app).bind_to_env(env)
          '''
          return self.__class__(self._scope, self._location,
                                path=self._path, host=self._host,
                                fragment=self._fragment,
                                ready=self._ready,
                                need_arguments=self._need_arguments,
                                finalize_params=self._finalize_params,
                                parent=self._parent,
                                bound_env=bound_env)