Fix: set mandatory modelName

Author: CodingCarlos

lib/model.js

@@ -1,10 +1,10 @@
 const models = {};
 
 function model(data, modelName) {
-	if(!data) {
+	if(!data || (!this.modelName && !modelName)) {
 		return this;
 	}
-	
+
 	// ToDo: Validate model
 	// ToDo: Check if model already exists to merge instead of set
 	var name = this.modelName || modelName;