<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="http://helloworld.de/StructureDefinition/Code" />
  <name value="Code" />
  <status value="draft" />
  <fhirVersion value="4.0.0" />
  <kind value="complex-type" />
  <abstract value="false" />
  <context>
    <type value="element" />
    <expression value="Address" />
  </context>
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension">
      <path value="Extension" />
      <short value="Optional Extensions Element" />
      <definition value="Optional Extension Element - found in all resources." />
      <constraint>
        <key value="ext-1" />
        <severity value="error" />
        <human value="Must have either extensions or value[x], not both" />
        <expression value="extension.exists() != value.exists()" />
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])" />
      </constraint>
      <mapping>
        <identity value="rim" />
        <map value="N/A" />
      </mapping>
    </element>
    <element id="Extension.value[x]">
      <path value="Extension.value[x]" />
      <type>
        <code value="code" />
      </type>
      <binding>
        <strength value="required" />
        <valueSet value="http://helloworld.de/ValueSet/quadrant" />
      </binding>
    </element>
  </differential>
</StructureDefinition>