Creates a new document from the "toDocument" parameter (usual rules apply in that it must be a valid document, with no existing documentId).
The compareDocument can be an existing documentId, or it too can be new as well.
- If existing (i.e. a valid DocumentId is supplied), it will be updated with any new data supplied before being sent to the comparison process.
- If new, then a new document will be created too, and the ID returned in the result.
The document scans are then sent for processing and comparison, such as comparing a selfie-video against a drivers licence photo.