/**
  * @return \yii\db\ActiveQuery
  */
 public function getSpecialist()
 {
     return $this->hasOne(Specialist::className(), ['id_specialist' => 'id_specialist']);
 }
 /**
  * @return \yii\db\ActiveQuery
  */
 public function getSpecialists()
 {
     return $this->hasMany(Specialist::className(), ['status' => 'id']);
 }