@Test
void composeToChar() {

    final ToChar<String> toChar = string -> string.toCharArray()[0];
    final ComposeToChar<String, String, ToChar<String>> composeToChar =
            (ComposeToChar<String, String, ToChar<String>>)
                    ComposedUtil.composeToChar(Function.identity(), toChar);
    assertNotNull(composeToChar.firstStep());
    assertNotNull(composeToChar.secondStep());
    assertEquals('t', composeToChar.applyAsChar("test"));
    assertNull(composeToChar.apply(null));
    assertNotNull(composeToChar.apply("test"));
}