public static ShapeMatcher<MemberShape> memberIsNullable(ValidatedResult<Model> result) {
        return ShapeMatcher.builderFor(MemberShape.class, result)
                .description("Member is marked with @required or @default trait")
                .addAssertion(member -> !member.hasTrait(RequiredTrait.ID),
                        member -> "Member is marked with the @required trait")
                .addAssertion(member -> {
                    DefaultTrait trait = member.getTrait(DefaultTrait.class).orElse(null);
                    return trait == null || trait.toNode().isNullNode();
                },
                        member -> "Member is marked with the @default trait")
                .build();
    }
Creates a matcher that ensures a member is not marked with @default or @required.

@param result The validated result to check.
@return Returns the created matcher.
smithy-model/src/test/java/software/amazon/smithy/model/ShapeMatcher.java