query: SELECT ?item ?country ?cat ?cat2
  {
    	?item wdt:P360 wd:Q16917 .
    	?a schema:about ?item . 
    	?a schema:isPartOf <https://www.wikidata.org/> .
  	OPTIONAL
    		{ 
        	?item wdt:P17 ?country .
        	?item wdt:P1754 ?cat .
          BIND( CONCAT("<strong class="error"><span class="scribunto-error" id="mw-scribunto-error-0">Script error: You must specify a function to call.</span></strong>") as ?cat2 )
  		}
  }