code: public function getCatValue($testSessionId, $assessmentSectionId, $key)
      {
          $extendedState = $this->getExtendedState($testSessionId);
          return $extendedState->getCatValue($assessmentSectionId, $key);
      }
docs: Get a CAT Value
  
  Get a CAT value from the Extended State.
  
  @param string $testSessionId
  @param string $assessmentSectionId
  @param string $key
  @return string
  @throws \common_Exception