code: public HalResource setEmbedded(String relation, HalResource resource) {
      if (resource == null) {
        return this;
      }
      return addResources(HalResourceType.EMBEDDED, relation, false, new HalResource[] {
          resource
      });
    }
docs: Embed resource for the given relation. Overwrites existing one.
  @param relation Embedded resource relation
  @param resource Resource to embed
  @return HAL resource