private static Model applyBaseTransforms(Model model) {
        ModelTransformer transformer = ModelTransformer.create();
        model = transformer.changeStringEnumsToEnumShapes(model);
        model = transformer.flattenAndRemoveMixins(model);
        return model;
    }
Applies standard transforms to the model.
<dl>
    <dt>changeStringEnumsToEnumShapes</dt>
    <dd>Changes string enums to enum shapes for compatibility</dd>
    <dt>flattenAndRemoveMixins</dt>
    <dd>Ensures mixins are flattened into any generated traits or nested structures</dd>
</dl>
smithy-trait-codegen/src/main/java/software/amazon/smithy/traitcodegen/TraitCodegen.java