docs: protected WsByteBuffer[] marshallBinaryHeader(WsByteBuffer[] inBuffers, HeaderElement elem) {
          if (elem.wasRemoved()) {
              return inBuffers;
          }
          WsByteBuffer[] buffers = inBuffers;
          final byte[] value = elem.asRawBytes();
          if (null != value) {
              HeaderKeys key = elem.getKey();
              if (!key.isUndefined()) {
                  buffers = putInt(GenericConstants.KNOWN_HEADER, buffers);
                  buffers = putInt(elem.getKey().getOrdinal(), buffers);
              } else {
                  buffers = putInt(GenericConstants.UNKNOWN_HEADER, buffers);
                  buffers = putInt(key.getByteArray().length, buffers);
                  buffers = putBytes(key.getByteArray(), buffers);
              }
              buffers = putInt(elem.getValueLength(), buffers);
              buffers = putBytes(value, elem.getOffset(), elem.getValueLength(), buffers);
  
              if (TraceComponent.isAnyTracingEnabled() && tc.isEventEnabled()) {
                  Tr.event(tc, "Marshalling: " + elem.getName()
                               + " [" + elem.getDebugValue() + "]");
              }
          }
          return buffers;
      }