graphdb/src/main/java/com/tinkerpop/blueprints/impls/orient/OrientBaseGraph.java
public OrientVertexType createVertexType(final String iClassName, final String iSuperClassName) {
    makeActive();
    return createVertexType(iClassName, iSuperClassName == null ? getVertexBaseType() : getVertexType(iSuperClassName));
  }
public OrientVertexType createVertexType(final String iClassName, final String iSuperClassName) {
    makeActive();
    return createVertexType(iClassName, iSuperClassName == null ? getVertexBaseType() : getVertexType(iSuperClassName));
  }
Creates a new Vertex persistent class specifying the super class.

@param iClassName      Vertex class name
@param iSuperClassName Vertex class name to extend

@return OrientVertexType instance representing the persistent class