import java.util.List; public class SuperBuilderBasicToBuilder { @lombok.experimental.SuperBuilder(toBuilder=true) public static class Parent { int field1; @lombok.Singular List items; } @lombok.experimental.SuperBuilder(toBuilder=true) public static class Child extends Parent { double field3; } public static void test() { Child x = Child.builder().field3(0.0).field1(5).item("").build().toBuilder().build(); } }