{
  "resourceType": "StructureDefinition",
  "url": "https://example.org/fhir/StructureDefinition/MySpecimen",
  "name": "MySpecimen",
  "status": "draft",
  "fhirVersion": "4.0.1",
  "kind": "resource",
  "abstract": false,
  "type": "Specimen",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Specimen",
  "derivation": "constraint",
  "differential": {
    "element": [
      {
        "id": "Specimen.identifier",
        "path": "Specimen.identifier",
        "short": "External Identifier1"
      }
    ]
  }
}