docs: protected Object transformEntity(Entity entity) throws JRException {
  		//log.debug("transforming group...");
  		DJGroup djgroup = (DJGroup) entity;
  		PropertyColumn column = djgroup.getColumnToGroupBy();
  		JRDesignGroup group = new JRDesignGroup();
  
  
  		group.setName(djgroup.getName());
  		
  		getLayoutManager().getReferencesMap().put(group.getName(), djgroup);
  
  		group.setCountVariable(new JRDesignVariable());
  
          JRDesignSection gfs = (JRDesignSection) group.getGroupFooterSection();
          gfs.getBandsList().add(new JRDesignBand());
  
  
          JRDesignSection ghs = (JRDesignSection) group.getGroupHeaderSection();
          ghs.getBandsList().add(new JRDesignBand());
  
  		JRDesignExpression jrExpression = new JRDesignExpression();
  		
  		CustomExpression expressionToGroupBy = column.getExpressionToGroupBy();
  		
  		if (expressionToGroupBy != null) { //new in 3.0.7-b5
  			useVariableForCustomExpression(group, jrExpression, expressionToGroupBy);
  			
  		} else {
  			if (column instanceof ExpressionColumn){
  				ExpressionColumn col = (ExpressionColumn)column;
  				CustomExpression customExpression = col.getExpression();
  				useVariableForCustomExpression(group, jrExpression, customExpression);
  			} else {
  				jrExpression.setText(column.getTextForExpression());
  				jrExpression.setValueClassName(column.getValueClassNameForExpression());
  			}
  		}
  		
  
  		group.setExpression(jrExpression);
  
  		return group;
  	}