/**
  * @return ilSkillSelectorGUI
  */
 private function buildSkillSelectorExplorerGUI($assignments)
 {
     require_once 'Services/Skill/classes/class.ilSkillSelectorGUI.php';
     $skillSelectorExplorerGUI = new ilSkillSelectorGUI($this, self::CMD_SHOW_SKILL_SELECT, $this, self::CMD_UPDATE_SKILL_QUEST_ASSIGNS, self::PARAM_SKILL_SELECTION);
     $skillSelectorExplorerGUI->setSelectMode(self::PARAM_SKILL_SELECTION, true);
     $skillSelectorExplorerGUI->setNodeOnclickEnabled(false);
     // parameter name for skill selection is actually taken from value passed to constructor,
     // but passing a non empty name to setSelectMode is neccessary to keep input fields enabled
     foreach ($assignments as $assignment) {
         $id = "{$assignment->getSkillBaseId()}:{$assignment->getSkillTrefId()}";
         //$skillSelectorExplorerGUI->setNodeSelected($id);
         $skillSelectorExplorerGUI->setSkillSelected($id);
     }
     return $skillSelectorExplorerGUI;
 }