@Test
public void testToCsv() {

    assertThat(Strings.toCsv(Collections.<String>emptyList()), is(""));
    assertThat(Strings.toCsv(Collections.singletonList("a")), is("a"));
    assertThat(Strings.toCsv(Arrays.asList("a", "b", "c")), is("a, b, c"));
}