http://hl7.org/fhir/StructureDefinition/Duration|4.0.1

{description: 'Base StructureDefinition for Duration Type: A length of time.', derivation: specialization, name: Duration, type: Duration, class: complex-type, kind: complex-type, url: 'http://hl7.org/fhir/StructureDefinition/Duration', base: 'http://hl7.org/fhir/StructureDefinition/Quantity', version: 4.0.1}