@Override
        public Void structureShape(StructureShape shape) {
            for (MemberShape member : shape.members()) {
                if (TraitCodegenUtils.isNullableMember(member)) {
                    writer.write("this.$L = $L;", symbolProvider.toMemberName(member), getBuilderValue(member));
                } else {
                    writer.write("this.$1L = $2T.requiredState($1S, $3L);",
                            symbolProvider.toMemberName(member),
                            SmithyBuilder.class,
                            getBuilderValue(member));
                }
            }
            return null;
        }
Generates the actual field initialization statements for each member of a shape.
smithy-trait-codegen/src/main/java/software/amazon/smithy/traitcodegen/generators/ConstructorGenerator.java