http://fhir.patientsknowbest.com/structuredefinition/upstream-last-updated
https://www.hl7.org/fhir/STU3/structuredefinition.html
description
Aggregated resources are modified versions of upstream resources (e.g. FHIR resources provide directly to a Customer box).
This extension is generated by PKB to capture the meta.lastUpdated value of the upstream resource.
context
This extension is used by many resources.
type
Extension
element type
dateTime