### Question:
BigDecimals { public static Mapper<BigDecimal, String> toPlainString() { return new Mapper<BigDecimal, String>() { @Override public String map(BigDecimal input) { return input.toPlainString(); } }; } private  BigDecimals(); static Mapper<String, BigDecimal> fromStringToBigDecimal(); static Mapper<Integer, BigDecimal> fromIntegerToBigDecimal(); static Mapper<Long, BigDecimal> fromLongToBigDecimal(); static Mapper<BigInteger, BigDecimal> fromBigIntegerToBigDecimal(); static Mapper<Double, BigDecimal> fromDoubleToBigDecimal(); static Mapper<BigDecimal, String> toPlainString(); static Mapper<BigDecimal, BigDecimal> toScaled(final Integer scale, final RoundingMode roundingMode); static BigDecimal bigDecimal(Integer value); static BigDecimal bigDecimal(Long value); static BigDecimal bigDecimal(Double value); static BigDecimal bigDecimal(String value);  }### Answer:
@Test public void returnsMapperFromBigDecimalToPlainString() { assertThat(toPlainString().map(new BigDecimal("123.456")), is("123.456")); }