code: private QualifiedName anyRef(String attributeName, JsonObject attributeMap) {
  	if (attributeMap.has(attributeName))
  	    return currentNamespace.stringToQualifiedName(popString(attributeMap,
  	                                              attributeName),
  	                                              pf);
  	else
  	    return null;
      }
docs: TODO: this name is legacy, what should it be?