public SmithyBuild transformFactory(Function<String, Optional<ProjectionTransformer>> transformFactory) {
        this.transformFactory = transformFactory;
        return this;
    }
Sets a factory function used to create transforms by name.

<p>A default implementation that utilizes Java SPI to discover
implementations of {@link ProjectionTransformer} will be
used if a custom factory is not provided.

@param transformFactory Factory that accepts a transform name and
 returns the optionally found transform.
@return Returns the builder.

@see ProjectionTransformer#createServiceFactory
smithy-build/src/main/java/software/amazon/smithy/build/SmithyBuild.java