Alias shouldn't have null values for compartment and complex id

frontend-js/src/main/js/map/data/Alias.js

@@ -236,14 +236,18 @@ Alias.prototype.getCompartmentId = function() {
 };
 
 Alias.prototype.setCompartmentId = function(compartmentId) {
-  this._compartmentId = compartmentId;
+  if (compartmentId !== null) {
+    this._compartmentId = compartmentId;
+  }
 };
 Alias.prototype.getComplexId = function() {
   return this._complexId;
 };
 
 Alias.prototype.setComplexId = function(complexId) {
-  this._complexId = complexId;
+  if (complexId !== null) {
+    this._complexId = complexId;
+  }
 };
 
 module.exports = Alias;