code: public static DefaultListOperation<ContentKeyInfo> list(
              LinkInfo<ContentKeyInfo> link) {
          return new DefaultListOperation<ContentKeyInfo>(link.getHref(),
                  new GenericType<ListResult<ContentKeyInfo>>() {
                  });
      }
docs: Create an operation that will list all the content keys at the given
  link.
  
  @param link
  Link to request content keys from.
  @return The list operation.