/**
  * Declares an association between this object and a ChildQuestions object.
  *
  * @param  ChildQuestions $v
  * @return $this|\ExpertQuestionState The current object (for fluent API support)
  * @throws PropelException
  */
 public function setQuestions(ChildQuestions $v = null)
 {
     if ($v === null) {
         $this->setQuestionId(NULL);
     } else {
         $this->setQuestionId($v->getId());
     }
     $this->aQuestions = $v;
     // Add binding for other direction of this n:n relationship.
     // If this object has already been added to the ChildQuestions object, it will not be re-added.
     if ($v !== null) {
         $v->addExpertQuestionState($this);
     }
     return $this;
 }