             return;
         
         var fullURL:String = baseURL.value;
+        
+        if (!fullURL)
+            return;
         
         var queryFrag:String = queryFragment();
         

        return query;
    }
    
    [xobjTransient]
    public function addSearchTerm(term:FilterTerm):void
    {
        if (!filterTerms)

        recomputeQualifiedURL();
    }
    
    public function removeSearchTerm(term:FilterTerm):void
    {
        var index:int = filterTerms.indexOf(term);
        if (index != -1)
        {
            filterTerms.splice(index,1);
        }
        
        recomputeQualifiedURL();
    }
    
    /* TODO: decide if headers really belong on resource spec */
    [xobjTransient]
    public var headers:Dictionary;
