docs: public CrosstabBuilder addColumn(String title, String property, String className, boolean showTotal) {
  		DJCrosstabColumn col = new CrosstabColumnBuilder()
  			.setProperty(property,className)
  			.setShowTotals(showTotal)
  			.setTitle(title)
  			.build();
  		addColumn(col);
  		return this;
  	}