### Question:
MaintainedPeers { public Stream<Peer> streamPeers() { return maintainedPeers.stream(); }  boolean add(final Peer peer); boolean remove(final Peer peer); boolean contains(final Peer peer); int size(); void subscribeAdd(final PeerAddedCallback callback); void subscribeRemove(final PeerRemovedCallback callback); Stream<Peer> streamPeers();  }### Answer:
@Test public void stream_empty() { final List<Peer> peers = maintainedPeers.streamPeers().collect(Collectors.toList()); assertThat(peers).isEmpty(); }