core/traits/RegistryTrait.php
public static function has($name)
    {
        return (self::find()->where([self::getNameAttribute() => $name])->one()) ? true : false;
    }
public static function has($name)
    {
        return (self::find()->where([self::getNameAttribute() => $name])->one()) ? true : false;
    }
public static function has ( $ name ) { return ( self :: find ( ) -> where ( [ self :: getNameAttribute ( ) => $ name ] ) -> one ( ) ) ? true : false ; }
Check whether a config value exists or not

@param string $name
@return boolean
Check whether a config value exists or not