code: public void resumeTransfer() {
          final ChannelHandlerContext ctx = this.ctx;
          if (ctx == null) {
              return;
          }
          if (ctx.executor().inEventLoop()) {
              resumeTransfer0(ctx);
          } else {
              // let the transfer resume on the next event loop round
              ctx.executor().execute(new Runnable() {
  
                  @Override
                  public void run() {
                      resumeTransfer0(ctx);
                  }
              });
          }
      }
docs: Continues to fetch the chunks from the input.