AcDbVertexRef::AcDbVertexRef(AcDbCompoundObjectId&, AcDbSubentId&, AcGePoint3d&) Constructor   

explicit AcDbVertexRef(
    const AcDbCompoundObjectId&, 
    const AcDbSubentId& = kNullSubentId, 
    const AcGePoint3d& = AcGePoint3d::kOrigin
);