docs: private List<WsByteBuffer> writeHeader(List<WsByteBuffer> list) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "Writing gzip header information");
          }
          WsByteBuffer hdr = HttpDispatcher.getBufferManager().allocateDirect(GZIP_Header.length);
          hdr.put(GZIP_Header);
          hdr.flip();
          list.add(hdr);
          this.haveWrittenHeader = true;
          return list;
      }