private static void handleUnknownTraitsOption(BuildOptions options, ModelAssembler assembler) {
        if (options.allowUnknownTraits()) {
            LOGGER.fine("Ignoring unknown traits");
            assembler.putProperty(ModelAssembler.ALLOW_UNKNOWN_TRAITS, true);
        }
    }
Loads, builds, and report validation issues with models.
smithy-cli/src/main/java/software/amazon/smithy/cli/commands/ModelBuilder.java