code: private String selectCompression(String encodingHeader)
      {
          // TODO, this could be a little more robust.
          // prefer gzip over deflate
          if (encodingHeader!=null)
          {
              if (encodingHeader.toLowerCase().contains(LZ4))
                  return LZ4;
              else if (encodingHeader.toLowerCase().contains(GZIP))
                  return GZIP;
              else if (encodingHeader.toLowerCase().contains(DEFLATE))
                  return DEFLATE;
          }
          return null;
      }
docs: /* ------------------------------------------------------------