yii\db\BaseActiveRecord::__get PHP Method

    public function __get($name)
    {
        if (isset($this->_attributes[$name]) || array_key_exists($name, $this->_attributes)) {
            return $this->_attributes[$name];
        } elseif ($this->hasAttribute($name)) {
            return null;
        } else {
            if (isset($this->_related[$name]) || array_key_exists($name, $this->_related)) {
                return $this->_related[$name];
            }
            $value = parent::__get($name);
            if ($value instanceof ActiveQueryInterface) {
                return $this->_related[$name] = $value->findFor($name, $this);
            } else {
                return $value;
            }
        }
    }