<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="https://example.org/fhir/StructureDefinition/MyQuantity" />
  <name value="MyQuantity" />
  <status value="draft" />
  <fhirVersion value="4.0.1" />
  <mapping>
    <identity value="v2" />
    <uri value="http://hl7.org/v2" />
    <name value="HL7 v2 Mapping" />
  </mapping>
  <mapping>
    <identity value="rim" />
    <uri value="http://hl7.org/v3" />
    <name value="RIM Mapping" />
  </mapping>
  <kind value="complex-type" />
  <abstract value="false" />
  <type value="Quantity" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Quantity" />
  <derivation value="constraint" />
  <differential>
    <element id="Quantity.comparator">
      <path value="Quantity.comparator" />
      <max value="0" />
    </element>
    <element id="Quantity.system">
      <path value="Quantity.system" />
      <fixedUri value="http://unitsofmeasure.org" />
      <mustSupport value="true" />
    </element>
    <element id="Quantity.code">
      <path value="Quantity.code" />
      <min value="1" />
    </element>
  </differential>
</StructureDefinition>