@SuppressWarnings("unchecked")
    public final M returningNew() {
      options.returnDocument(ReturnDocument.AFTER);
      return (M) this;
    }
Configures this modifier so that new (updated) version of document will be returned in
case of successful update.
@see #returningOld()
@return {@code this} modifier for chained invocation
mongo/src/org/immutables/mongo/repository/Repositories.java