code: public static Buffer wrap(final Buffer one, final Buffer two) {
          // TODO: create an actual composite buffer. 
          final int size1 = one != null ? one.getReadableBytes() : 0;
          final int size2 = two != null ? two.getReadableBytes() : 0;
          if (size1 == 0 && size2 > 0) {
              return two.slice();
          } else if (size2 == 0 && size1 > 0) {
              return one.slice();
          } else if (size2 == 0 && size1 == 0) {
              return Buffers.EMPTY_BUFFER;
          }
  
          final Buffer composite = Buffers.createBuffer(size1 + size2);
          one.getBytes(composite);
          two.getBytes(composite);
          return composite;
      }
docs: Combine two buffers into one. The resulting buffer will share the
  underlying byte storage so changing the value in one will affect the
  other. However, the original two buffers will still have their own reader
  and writer index.
  
  @param one
  @param two
  @return