class TestlabViewItems extends TestlabCkViewItems
{
	protected function displayDefault($tpl = null)
	{			
    	echo("Forked");  // Fork and replace the original function
  	}
		
	public function display($tpl = null)
	{
		 echo("Forked"); 
	}
}

public static function loadFork($file)
	{		
		//Transform the file path to reach the fork directory
		$file = preg_replace("#com_projectlab#", 'com_projectlab' .DS. 'fork', $file);		
		// Load the fork file.
		if (!empty($file) && file_exists($file)){
			include_once($file);
			echo("Loading Fork". $file);			
		}
	}

protected function displayAddissue($tpl = null)
	{
		$document	= JFactory::getDocument();
		$this->title = JText::_("PROJECTLAB_LAYOUT_ADD_ISSUE");
		$document->title = $document->titlePrefix . $this->title . $document->titleSuffix;
              
             [...]		

		$model_issue_type = CkJModel::getInstance('Itemtypes', 'ProjectlabModel');
		$model_issue_type->addGroupOrder("a.name");
Added==>[b]$model_issue_type->addWhere ("a.table   LIKE '%issue%'");[/b]
		$lists['fk']['issue_type'] = $model_issue_type->getItems();

		$model_milestone_id = CkJModel::getInstance('Milestones', 'ProjectlabModel');
		$model_milestone_id->addGroupOrder("a.title");
		$lists['fk']['milestone_id'] = $model_milestone_id->getItems();
	}