4.3/final/images/null-annotations-for-fields-examples.txt

import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;

public class NullAnnotatedFields {
    @NonNull Letter nonNull;
    @Nullable Letter nullable;
    String test() {
        nonNull.print();
        nullable.print();
        nonNull = null;

        if (nullable != null)
            nullable.print(); // protected

        nullable = new Letter();
        bar();     // spoils protection
        return nullable.toString();
    }
    void bar() {
       
    }
}
// --- not shown in the screenshot: --- 
class Letter {
    void print() {}
}