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

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