static Function<String, Optional<ProjectionTransformer>> createServiceFactory(ClassLoader classLoader) {
        return createServiceFactory(ServiceLoader.load(ProjectionTransformer.class, classLoader));
    }
Creates a {@code ProjectionTransformer} factory function using SPI.

@param classLoader Class loader to use to discover classes.
@return Returns the created factory function.
smithy-build/src/main/java/software/amazon/smithy/build/ProjectionTransformer.java