// Factory for SignatureLoadModel.
private static ITransformer Create(IHostEnvironment env, ModelLoadContext ctx)
{
Contracts.CheckValue(env, nameof(env));
env.CheckValue(ctx, nameof(ctx));
ctx.CheckAtModel(GetVersionInfo());
var contractName = ctx.LoadString();
var composition = env.GetCompositionContainer();
ITransformer transformer = composition.GetExportedValue <ITransformer>(contractName);
return(transformer);
}