public void testConverterToForward() {
    assertThat(UPPER_UNDERSCORE.converterTo(UPPER_CAMEL).convert("FOO_BAR")).isEqualTo("FooBar");
    assertThat(UPPER_UNDERSCORE.converterTo(LOWER_CAMEL).convert("FOO_BAR")).isEqualTo("fooBar");
    assertThat(UPPER_CAMEL.converterTo(UPPER_UNDERSCORE).convert("FooBar")).isEqualTo("FOO_BAR");
    assertThat(LOWER_CAMEL.converterTo(UPPER_UNDERSCORE).convert("fooBar")).isEqualTo("FOO_BAR");
  }

        };
    Function<Object, String> backward = toStringFunction();

    Converter<String, Number> converter = Converter.<String, Number>from(forward, backward);

    assertNull(converter.convert(null));
    assertNull(converter.reverse().convert(null));

    assertEquals((Integer) 5, converter.convert("5"));
    assertEquals("5", converter.reverse().convert(5));
  }

    Converter<String, Integer> converter = Ints.stringConverter();
    assertThat(converter.convert("1")).isEqualTo(1);
    assertThat(converter.convert("0")).isEqualTo(0);
    assertThat(converter.convert("-1")).isEqualTo(-1);
    assertThat(converter.convert("0xff")).isEqualTo(255);
    assertThat(converter.convert("0xFF")).isEqualTo(255);
    assertThat(converter.convert("-0xFF")).isEqualTo(-255);

  }

  public void testStringConverter_convert() {
    Converter<String, Double> converter = Doubles.stringConverter();
    assertThat(converter.convert("1.0")).isEqualTo(1.0);
    assertThat(converter.convert("0.0")).isEqualTo(0.0);
    assertThat(converter.convert("-1.0")).isEqualTo(-1.0);
    assertThat(converter.convert("1")).isEqualTo(1.0);
    assertThat(converter.convert("0")).isEqualTo(0.0);

    Converter<String, Long> converter = Longs.stringConverter();
    assertThat(converter.convert("1")).isEqualTo(1L);
    assertThat(converter.convert("0")).isEqualTo(0L);
    assertThat(converter.convert("-1")).isEqualTo(-1L);
    assertThat(converter.convert("0xff")).isEqualTo(255L);
    assertThat(converter.convert("0xFF")).isEqualTo(255L);
    assertThat(converter.convert("-0xFF")).isEqualTo(-255L);

    Converter<String, Short> converter = Shorts.stringConverter();
    assertThat(converter.convert("1")).isEqualTo(1);
    assertThat(converter.convert("0")).isEqualTo(0);
    assertThat(converter.convert("-1")).isEqualTo(-1);
    assertThat(converter.convert("0xff")).isEqualTo(255);
    assertThat(converter.convert("0xFF")).isEqualTo(255);
    assertThat(converter.convert("-0xFF")).isEqualTo(-255);

    Converter<String, Integer> converter = Ints.stringConverter();
    assertThat(converter.convert("1")).isEqualTo(1);
    assertThat(converter.convert("0")).isEqualTo(0);
    assertThat(converter.convert("-1")).isEqualTo(-1);
    assertThat(converter.convert("0xff")).isEqualTo(255);
    assertThat(converter.convert("0xFF")).isEqualTo(255);
    assertThat(converter.convert("-0xFF")).isEqualTo(-255);

  }

  public void testStringConverter_convert() {
    Converter<String, Double> converter = Doubles.stringConverter();
    assertThat(converter.convert("1.0")).isEqualTo(1.0);
    assertThat(converter.convert("0.0")).isEqualTo(0.0);
    assertThat(converter.convert("-1.0")).isEqualTo(-1.0);
    assertThat(converter.convert("1")).isEqualTo(1.0);
    assertThat(converter.convert("0")).isEqualTo(0.0);

  public void testStringConverter_convert() {
    Converter<String, Float> converter = Floats.stringConverter();
    assertThat(converter.convert("1.0")).isEqualTo(1.0f);
    assertThat(converter.convert("0.0")).isEqualTo(0.0f);
    assertThat(converter.convert("-1.0")).isEqualTo(-1.0f);
    assertThat(converter.convert("1")).isEqualTo(1.0f);
    assertThat(converter.convert("0")).isEqualTo(0.0f);

  public void testStringConverter_convert() {
    Converter<String, Float> converter = Floats.stringConverter();
    assertThat(converter.convert("1.0")).isEqualTo(1.0f);
    assertThat(converter.convert("0.0")).isEqualTo(0.0f);
    assertThat(converter.convert("-1.0")).isEqualTo(-1.0f);
    assertThat(converter.convert("1")).isEqualTo(1.0f);
    assertThat(converter.convert("0")).isEqualTo(0.0f);