// create a DiskLoc object DiskLoc myLoc; // check if the DiskLoc object is null using isNull method if (myLoc.isNull()) { cout << "The DiskLoc object is null" << endl; } else { cout << "The DiskLoc object is not null" << endl; }In the above example, we create a DiskLoc object called myLoc and use the isNull method to check if it is null or not. The DiskLoc isNull method is part of the MongoDB C++ driver library, which is a package that provides a high-level API for connecting to MongoDB using C++ programming language.