How 'Basic' can be used for essoteric resources - in this case, a UML class model

@prefix fhir: <http://hl7.org/fhir/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

# - resource -------------------------------------------------------------------

[a fhir:Basic;
  fhir:nodeRole fhir:treeRoot;
  fhir:Resource.id [ fhir:value "classModel"];
  fhir:DomainResource.text [
     fhir:Narrative.status [ fhir:value "generated" ];
     fhir:Narrative.div "<div xmlns=\"http://www.w3.org/1999/xhtml\">\n      <p><b>Class1</b></p>\n      <ul>\n        <li>Attribute1: 1..*</li>\n        <li>Attribute2: 0..1</li>\n      </ul>\n    </div>"
  ];
  fhir:DomainResource.extension [
     fhir:index 0;
     fhir:Extension.url [ fhir:value "http://example.org/do-not-use/fhir-extensions/UMLclass" ];
     fhir:Element.extension [
       fhir:index 0;
       fhir:Extension.url [ fhir:value "name" ];
       fhir:Extension.valueString [ fhir:value "Class1" ]
     ], [
       fhir:index 1;
       fhir:Extension.url [ fhir:value "attribute" ];
       fhir:Element.extension [
         fhir:index 0;
         fhir:Extension.url [ fhir:value "name" ];
         fhir:Extension.valueString [ fhir:value "attribute1" ]
       ], [
         fhir:index 1;
         fhir:Extension.url [ fhir:value "minOccurs" ];
         fhir:Extension.valueInteger [ fhir:value "1"^^xsd:integer ]
       ], [
         fhir:index 2;
         fhir:Extension.url [ fhir:value "maxOccurs" ];
         fhir:Extension.valueCode [ fhir:value "*" ]
       ]
     ], [
       fhir:index 2;
       fhir:Extension.url [ fhir:value "attribute" ];
       fhir:Element.extension [
         fhir:index 0;
         fhir:Extension.url [ fhir:value "name" ];
         fhir:Extension.valueString [ fhir:value "attribute2" ]
       ], [
         fhir:index 1;
         fhir:Extension.url [ fhir:value "minOccurs" ];
         fhir:Extension.valueInteger [ fhir:value "0"^^xsd:integer ]
       ], [
         fhir:index 2;
         fhir:Extension.url [ fhir:value "maxOccurs" ];
         fhir:Extension.valueInteger [ fhir:value "1"^^xsd:integer ]
       ]
     ]
  ];
  fhir:Basic.code [
     fhir:CodeableConcept.coding [
       fhir:index 0;
       fhir:Coding.system [ fhir:value "http://example.org/do-not-use/fhir-codes#resourceTypes" ];
       fhir:Coding.code [ fhir:value "UMLCLASSMODEL" ]
     ]
  ]] .

# - ontology header ------------------------------------------------------------

[a owl:Ontology;
  owl:imports fhir:fhir.ttl] .

# -------------------------------------------------------------------------------------