code: @SuppressWarnings("rawtypes")
      @Override
      public long sizeInputStreamData(Map isd) throws UnsupportedEncodingException, IllegalStateException {
          validateInputStreamData(isd);
          // The length of IMPUT_STREAM_CONTENT_TYPE won't exceed Integer.MAX_VALUE
          long size = LENGTH_INT + LENGTH_LONG;
          String type = (String)isd.get(INPUT_STREAM_CONTENT_TYPE);
          if (type != null) {
              size += type.getBytes("UTF-8").length;
          } else {
              size +=1; // if the size is zero, one byte data will be used for placeholder.
          }
          byte [] data = (byte [])isd.get(INPUT_STREAM_CONTENT_DATA);
          if (data != null) {
              size += data.length;
          }
          if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled()&&logger.isLoggable (Level.FINE))
              logger.logp(Level.FINE, CLASS_NAME,"sizeInputStreamData", Long.toString(size));
          return size;
      }
docs: returns estimated size of serialized InputStreamData
  this code does not consider that the length in long overwraps.