code: public static StringBuilder getBufferTraceInfo(StringBuilder src, WsByteBuffer buffer) {
          StringBuilder sb = (null == src) ? new StringBuilder(64) : src;
          if (null == buffer) {
              return sb.append("null");
          }
          sb.append("hc=").append(buffer.hashCode());
          sb.append(" pos=").append(buffer.position());
          sb.append(" lim=").append(buffer.limit());
          sb.append(" cap=").append(buffer.capacity());
          return sb;
      }
docs: This method is called for tracing in various places. It returns a string that
  represents the buffer including hashcode, position, limit, and capacity.
  
  @param src
  @param buffer buffer to get debug info on
  @return StringBuilder