Help in pub.schema:validate

I have built a small flow service which output a valid well formed XML node.
The user has to input an XML document file path and the name of a document schema to validate it with the output node.
When I validate the xml documents to the schemas using an external “Mapping - 3.xml” will be valid and “Mapping - 5.xml” will be invalid because the Key element text has to be unique.
But when I built my flow service I got both xml files valid???

Any idea about using the xsd:unique/ from the XML Schema in webmethod ???
Mapping.xsd (1.25 KB)
Mapping - 3.xml (462 Bytes)
Mapping - 5.xml (462 Bytes)

I dont think wM supports this.