public String serviceTitle(String fallback) {
        return shape().getTrait(TitleTrait.class).map(TitleTrait::getValue).orElse(fallback);
    }
Attempts to get the title of service from the model, returning the fallback value
if the service does not have a {@link TitleTrait}.

@param fallback string to return if service does not have a title
@return title of service
smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/directed/GenerateServiceDirective.java