code: def _fill_lookup_prop(self, testsuites_properties):
          
          if not self._lookup_prop:
              raise Dump2PolarionException("Failed to set the 'polarion-lookup-method' property")
  
          etree.SubElement(
              testsuites_properties,
              "property",
              {"name": "polarion-lookup-method", "value": self._lookup_prop},
          )
docs: Fills the polarion-lookup-method property.