code: protected function getLockAttribute()
      {
          if ($this->_lockAttribute) {
              return $this->_lockAttribute;
          }
  
          /* @var $owner BaseActiveRecord */
          $owner = $this->owner;
          $lock = $owner->optimisticLock();
          if ($lock === null || $owner->hasAttribute($lock) === false) {
              throw new InvalidCallException("Unable to get the optimistic lock attribute. Probably 'optimisticLock()' method is misconfigured.");
          }
          $this->_lockAttribute = $lock;
          return $lock;
      }
docs: Returns the column name to hold the version value as defined in [[\yii\db\BaseActiveRecord::optimisticLock()|optimisticLock()]].
  @return string the property name.
  @throws InvalidCallException if [[\yii\db\BaseActiveRecord::optimisticLock()|optimisticLock()]] is not properly configured.
  @since 2.0.16