A @PreviousTransformer() attribute written on Rejected features.
Our team has extensive "Error catching" for workspaces, where we create "error reports" for features which are rejected from transformers. We typically use an AttributeCreator, and nearly every one lists the previous transformer for faster debugging. Having this attribute would enable us to create presets and/or an Error Report Custom Transformer for many rejected ports, rather than many, many AttributeCreators for the various transformers with rejected ports.