We have a situation where we want to save the patient photo (or any other attachment) received via FHIR to a persistent property without decoding it. When it is sent out again using FHIR is is stored in the encoded format and need not be encoded. We do not need to decode it for our application. We always use it on another system that retrieves it or saves it via FHIR and therefore it is always received or sent embedded in JSON.