{
  "resourceType": "StructureDefinition",
  "name": "testExtension",
  "kind": "complex-type",
  "abstract": false,
  "contextType": "resource",
  "context": [
    "Basic"
  ],
  "type": "Extension",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation": "constraint",
  "differential": {
    "element": [
      {
        "id": "Extension.valueString",
        "path": "Extension.valueString",
        "type": [
          {
            "code": "string"
          }
        ]
      }
    ]
  }
}