Hotfix: comparator : null setting doesn't clear the comparator in the subclass

Author: Vlad Balin

dist/index.js

@@ -90,7 +90,7 @@ export class Collection< R extends Record = Record> extends Transactional implem
             this.prototype._itemEvents = eventsMap;
         }
 
-        if( definition.comparator ) this.prototype.comparator = definition.comparator;
+        if( definition.comparator !== void 0 ) this.prototype.comparator = definition.comparator;
 
         Transactional.onDefine.call( this, definition );
     }

dist/index.js.map

@@ -2880,7 +2880,7 @@ var Collection = (function (_super) {
             eventsMap.addEventsMap(definition.itemEvents);
             this.prototype._itemEvents = eventsMap;
         }
-        if (definition.comparator)
+        if (definition.comparator !== void 0)
             this.prototype.comparator = definition.comparator;
         Transactional.onDefine.call(this, definition);
     };