A DESCRIPTION OF THE PROBLEM :
Insted of writing three lines of code:

if ( someRef == null ) {
    someRef = new SomeClass();
}

just write one line:

someRef ??= new SomeClass();

This improves readability and speeds up coding. The double questionmark can also be used in variable assigment like

someRef = someMethod() ?? new SomeClass();

which ensures in one line that someRef does not become null even if someMethod returns null.