@Test
public void ping () throws Exception {

  val name1 = createName();
  val name2 = createName();
  node = Nodes.singleNode(name1, NodeConfig.builder()
                          .shortName(true)
                          .cookie("secret")
                          .build()
  );
  assertThat(node.ping(ELIXIR_ECHO_SERVER))
      .isTrue();
  assertThat(node.ping(ELIXIR_ECHO_SERVER))
      .isTrue();
  assertThat(node.ping(ELIXIR_ECHO_SERVER))
      .isTrue();
  assertThat(node.ping(ELIXIR_ECHO_SERVER))
      .isTrue();
  assertThat(node.ping(name1))
      .isTrue();
  assertThat(node.ping(name2))
      .isFalse();
  try (val node2 = Nodes.singleNode(name2, NodeConfig.builder()
                                    .shortName(true)
                                    .cookie("secret")
                                    .build())) {
    assertThat(node.ping(name2))
        .isTrue();
    assertThat(node2.ping(name1))
        .isTrue();
  }
}