code: public String getDocUrl(String className) {
          
          if(!cache.containsKey(className)) {
              String url = resolveDocByClass(className);
              if(url == null) {
                  url = resolveDocByPackage(className);
              }
              cache.put(className, url);
          }
          return cache.get(className);
          
          
         
      }
docs: Returns a HTTP URL for a class.
  
  @param className Name of a class to find URL for.
  
  @return HTTP URL for a class.