code: @Override
      public WsByteBuffer allocateFileChannelBuffer(FileChannel fc) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "allocateFileChannelBuffer");
          }
          return new FCWsByteBufferImpl(fc);
      }
docs: Allocate a buffer which will use tha FileChannel until the buffer needs
  to be used in a "non-FileChannel" way.
  
  @param fc FileChannel to use for this buffer
  @return FCWsByteBuffer buffer which can now be used.