protected function throwExceptionIfKeyPropertyIsMissing ($propsNames) {
		$propsNames = func_get_args();
		$selfClass = version_compare(PHP_VERSION, '5.5', '>') ? self::class : __CLASS__;
		throw new \LogicException(
			"[".$selfClass."] Route configuration property/properties is/are"
			." missing: `" . implode("`, `", $propsNames) . "`, to parse and"
			." complete key properties `match` and/or `reverse` to route"
			." or build URL correctly ($this)."
		);
	}