public function getFamiliarity($user = null)
    {
        if (is_null($user)) {
            $user = $this->getUser(false);
        }
        if (is_object($user)) {
            $user = $user->primaryKey;
        }
        $familarityKey = md5($user);
        if (!isset($this->_familiarity[$familarityKey])) {
            $this->_familiarity[$familarityKey] = false;
            $familiarityClass = Yii::$app->classes['ObjectFamiliarity'];
            if (!empty($user)) {
                $attributes = [];
                $attributes[$this->objectField] = $this->owner->primaryKey;
                $attributes[$this->userField] = $user;
                $this->_familiarity[$familarityKey] = $familiarityClass::find()->where($attributes)->one();
                if (empty($this->_familiarity[$familarityKey])) {
                    $this->_familiarity[$familarityKey] = new $familiarityClass();
                    $this->_familiarity[$familarityKey]->attributes = $attributes;
                }
            }
        }

        return $this->_familiarity[$familarityKey];
    }