code: void removeClientChannel(HttpRoute httpRoute, Http2ClientChannel http2ClientChannel) {
          EventLoopPool.PerRouteConnectionPool perRouteConnectionPool = fetchPerRoutePool(httpRoute,
                                                                                          http2ClientChannel.getChannel()
                                                                                              .eventLoop());
          if (perRouteConnectionPool != null) {
              perRouteConnectionPool.removeChannel(http2ClientChannel);
          }
      }
docs: Remove http/2 client channel from per route pool.
  
  @param httpRoute          the http route
  @param http2ClientChannel represents the http/2 client channel to be removed