code: public <T extends RiakIndex<?>> boolean hasIndex(RiakIndex.Name<T> name)
      {
          return indexes.containsKey(name.getFullname());
      }
docs: Returns whether a specific RiakIndex is present
  @param name the {@link RiakIndex.Name} representing the index to check for
  @return {@code true} if the index is present, {@code false} otherwise