docs: @Override
    public StringBuilder appendToBuffer(StringBuilder buf) {
      buf.append(super.getTask());
      if (isComplete()) {
        buf.append(": complete.");
      } else {
        buf.append(" #").append(getProcessed()+1).append('/').append(getTotal());
        buf.append(": ").append(getStepTitle());
      }
      buf.append('\n');
      return buf;
    }