code: public <T> T getLocal (Class<T> key)
      {
          for (Object attr : _locattrs) {
              if (key.isInstance(attr)) {
                  return key.cast(attr);
              }
          }
          return null;
      }
docs: Retrieves a local attribute for the supplied key. See {@link #setLocal} for
  information on key polymorphism. Returns null if no attribute is found that matches the
  supplied key.