### Question:
CharTransformer implements Transformer<Character, String> { @Override public String out(final Character o) { if (o == null) { return null; } return String.valueOf(o); }  @Override Character in(final String o); @Override String out(final Character o);  }### Answer:
@Test public void shouldFormatCharAsString() { final String actual = new CharTransformer().out('a'); assertThat(actual).isEqualTo("a"); }