@Override
        public void run() {
            if (member.hasNonNullDefault()) {
                this.defaultValue = member.expectTrait(DefaultTrait.class).toNode();
                member.accept(this);
            }
        }
Adds default values to builder properties.
smithy-trait-codegen/src/main/java/software/amazon/smithy/traitcodegen/generators/BuilderGenerator.java