code: public function removeCatValue($assessmentSectionId, $key)
      {
          if (isset($this->state[self::VAR_CAT]) && isset($this->state[self::VAR_CAT][$assessmentSectionId]) && isset($this->state[self::VAR_CAT][$assessmentSectionId][$key])) {
              unset($this->state[self::VAR_CAT][$assessmentSectionId][$key]);
          }
          return $this;
      }
docs: Removes a CAT value from the ExtendedState.
  @param string $assessmentSectionId
  @param string $key
  @return ExtendedState