code: protected void addPrevRenderedRow(final Object rowKey) {
  		WTableComponentModel model = getOrCreateComponentModel();
  		if (model.prevRenderedRows == null) {
  			model.prevRenderedRows = new HashSet<>();
  		}
  		model.prevRenderedRows.add(rowKey);
  	}
docs: Track the row keys that have been rendered.
  <p>
  Note - Only used for when the table is editable.
  </p>
  
  @param rowKey the row key that has been rendered.