docs: public ServerList filterOutObservers()
      {
          Iterable<ServerSpec> filtered = Iterables.filter
          (
              specs,
              new Predicate<ServerSpec>()
              {
                  @Override
                  public boolean apply(ServerSpec spec)
                  {
                      return spec.getServerType() != ServerType.OBSERVER;
                  }
              }
          );
          return new ServerList(Lists.newArrayList(filtered));
      }