bug with webix.extend

webix.extend({a:false}, {a:true}) 

// except {a: false}, but got { a: true}
L78#webix_debug.js@4.3.9
//copy methods, overwrite existing ones in case of conflict
	for (var method in source)
		if (!base[method] || force) // -> should be if(!method in base || force)?
			base[method] = source[method];

Yep, agree.
The same fix will be included in the oncoming Webix 4.4