LongTypeConverter implements TypeConverter<String, Long> { @Override public Long convert(final String value) { Utils.checkArgument(value != null, "Value to convert must not be null"); Utils.checkArgument(!value.isEmpty(), "Value to convert must not be empty"); return Double.valueOf(value).longValue(); }  @Override Long convert(final String value);  }
@Test public void whenInputIsLegalValue_ThenShouldReturnLong() { assertThat(converter.convert("5")).isEqualTo(5L); assertThat(converter.convert("5.0")).isEqualTo(5L); }