code: public Service getService(String type, String name) {
          for (int i = 0; i < configs.length; i++) {
              Provider p = getProvider(i);
              Service s = p.getService(type, name);
              if (s != null) {
                  return s;
              }
          }
          return null;
      }
docs: Return a Service describing an implementation of the specified
  algorithm from the Provider with the highest precedence that
  supports that algorithm. Return null if no Provider supports this
  algorithm.