valueX:
| "valueInteger"
| "valueUnsignedInt"
| "valuePositiveInt"
| "valueDecimal"
| "valueDateTime"
| "valueDate"
| "valueTime"
| "valueInstant"
| "valueString"
| "valueUri"
| "valueOid"
| "valueUuid"
| "valueId"
| "valueBoolean"
| "valueCode"
| "valueMarkdown"
| "valueBase64Binary"
| "valueCoding"
| "valueCodeableConcept"
| "valueAttachment"
| "valueIdentifier"
| "valueQuantity"
| "valueSampledData"
| "valueRange"
| "valuePeriod"
| "valueRatio"
| "valueHumanName"
| "valueAddress"
| "valueContactPoint"
| "valueTiming"
| "valueReference"
| "valueAnnotation"
| "valueSignature"
| "valueMeta"