{description: Data Element for ElementDefinition.constraint.key, package_name: hl7.fhir.r5.core, derivation: specialization, name: ElementDefinition.constraint.key, type: ElementDefinition.constraint.key, package_version: 4.5.0, class: logical, kind: logical, url: 'http://hl7.org/fhir/StructureDefinition/de-ElementDefinition.constraint.key', base: 'http://hl7.org/fhir/StructureDefinition/Element', version: 4.5.0}