@Test
void isSocket() {

    final Throwable t = new SocketException("Testing");
    assertThat(Util.isNetworkProblem(t)).isTrue();
    final Throwable t2 = new IllegalStateException(t);
    assertThat(Util.isNetworkProblem(t2)).isTrue();
    final Throwable t3 = new IllegalStateException();
    assertThat(Util.isNetworkProblem(t3)).isFalse();
    assertThat(Util.isNetworkProblem(null)).isFalse();
}