Adding _MapFactory class.
Adding _TypeChecker class. Its job is to ensure data match with its generic in the corresponding field.
Adding getRule(), to get all rules in the corresponding field.
Adding _Validator() class, which invoke new Rule().execute().
Remove _getDataRepresentation() and _typeChecker() from ModelFactory to _TypeChecker().
Adding toMap() and validate().
Adding test ModelFactory().create(), test Model.toMap() and unfinished validation test.
Adding test/packages/