code: public boolean diff(Node right, Buffer rightBuffer) throws IOException {
          Buffer leftBuffer;
          int leftChunk;
          int rightChunk;
          boolean result;
  
          leftBuffer = getWorld().getBuffer();
          try (InputStream leftSrc = newInputStream();
               InputStream rightSrc = right.newInputStream()) {
              result = false;
              do {
                  leftChunk = leftBuffer.fill(leftSrc);
                  rightChunk = rightBuffer.fill(rightSrc);
                  if (leftChunk != rightChunk || leftBuffer.diff(rightBuffer, leftChunk)) {
                      result = true;
                      break;
                  }
              } while (leftChunk > 0);
          }
          return result;
      }
docs: cheap diff if you only need a yes/no answer