final AddonFactory addonFactory = addonByKey.get(addOnSignature);
if (addonFactory == null) { throw new Exception("UIBuilder: AddOn factory not found for signature: " + addOnSignature + ", available: " + addonByKey.keySet()); }
ptObject = addonFactory.newAddon();
if (ptObject == null) { throw new Exception("UIBuilder: Failed to instanciate an Addon of type: " + addOnSignature); }
ptObject.create(instruction, this);
} else {
ptObject = uiFactory.newUIObject(this, instruction);
ptObject.create(instruction, this);
}