How do I create a Vertex with mandatory values in 3.1.1 MultiModel API

We are migrating from Tinkerpop 2.6 to MMAPI but could find the way to create a vertex with mandatory values.
In Tinkerpop we do this:
OrientGraphFactory factory = new OrientGraphFactory(“remote:localhost/ogm-test”, “root”, “toor”).setupPool(1, 10);
OrientGraph g = factory.getTx();
OrientVertex v1 = g.addVertex(“class:SimpleVertexEx”,“svex”,“directTest”);

and in MMAPI:
OrientDB dbServer = new OrientDB(“remote:localhost”,OrientDBConfig.defaultConfig());
ODatabaseSession db = dbServer.open(“ogm-test”, “root”, “toor”);
db.begin();

OVertex v1 = db.newVertex(“class:SimpleVertexEx”);
v1.setProperty(“svex”,“directTest”);
v1.save();

but this fail at newVertex line. How must we do that?

I make a mistake translating the code.
In Tinker you must put “class:xxxx” but that is not necessary in MMAPI.
The correct statement is:
OVertex v1 = db.newVertex(“SimpleVertexEx”);

and you get a vertex.