@lombok.Builder class BuilderBrokenExtension { public static @java.lang.SuppressWarnings("all") interface TextDef { public IdDef text(final String text); } public static @java.lang.SuppressWarnings("all") interface IdDef { public OptionalDef id(final int id); } public static @java.lang.SuppressWarnings("all") interface OptionalDef { public BuilderBrokenExtension build(); } private static @java.lang.SuppressWarnings("all") class $Builder implements TextDef, IdDef, OptionalDef { private String text; private int id; public IdDef text(final String text) { this.text = text; return this; } public OptionalDef id(final int id) { this.id = id; return this; } public BuilderBrokenExtension build() { return new BuilderBrokenExtension(this); } private $Builder() { super(); } } private final String text; private final int id; private @lombok.Builder.Extension void brokenExtension() { this.id = 42; } private @java.lang.SuppressWarnings("all") BuilderBrokenExtension(final $Builder builder) { super(); this.text = builder.text; this.id = builder.id; } public static @java.lang.SuppressWarnings("all") TextDef builderBrokenExtension() { return new $Builder(); } }