code: @Override
      public void finishedPart() {
          if (_docReader == null)
              throw new IllegalStateException("_docReader is not defined");
          _docReader.finish();
          _onDocument.onDocument(_docReader.getDocumentProperties(), _docReader.getDocumentSize());
          _docReader = null;
          Log.v(TAG, "%s: Finished document", this);
      }
docs: This method is called when a part is complete.