static function checkArg($argName, $argValue)
    {
        if (!($argValue instanceof self)) Checker::throwError($argName, $argValue, __CLASS__);
    }
static function checkArg($argName, $argValue)
    {
        if (!($argValue instanceof self)) Checker::throwError($argName, $argValue, __CLASS__);
    }
static function checkArg ( $ argName , $ argValue ) { if ( ! ( $ argValue instanceof self ) ) Checker :: throwError ( $ argName , $ argValue , __CLASS__ ) ; }
Use this to check that a function argument is of type `AppInfo`

@internal
Use this to check that a function argument is of type AppInfo