code: public OutputContext borrowOutputContext() {
          if (!hasOutput()) {
              return null;
          }
  
          OutputContext ctx = new OutputContext(pending);
          pending = null;
          return ctx;
      }
docs: Temporarily borrow the head chunk of the output buffers. This may be used
  to efficiently send responses or perform socket/buffer manipulation.
  
  When done with the context, ensure to call {@link #returnOutputContext(OutputContext)}
  
  @return The output context