code: public String retrieve(String entityID, String propertyID) throws Exception {
  		
  		// first step
  		String wikiDataReq = "https://www.wikidata.org/w/api.php?action=wbgetclaims&entity=" + entityID + "&property=" + propertyID + "&format=json";
  		
  		// (2) request for getting the image name
  		String imageName = processWikidataRequest(wikiDataReq, entityID, propertyID);
  		
  		// TODO
  		// encode imageName (blank spaces)
  		String encodedImageName = _encode (imageName);
  		
  	
  		// (3) Wikimedia 
  		String wikimediaReq = "https://commons.wikimedia.org/w/api.php?action=query&prop=imageinfo&iiprop=url&titles=File:" + encodedImageName + "&format=json";
  		
  		// (4) get URL
  		return getImageURLFromWikimedia(wikimediaReq);
  		
  	}
docs: propertyID: either P18 or P154