public static BigDecimal toWei(String number, Unit unit) {
        return toWei(new BigDecimal(number), unit);
    }
@Test
    public void testToWei() {
        assertEquals(Convert.toWei("21", Convert.Unit.WEI), (new BigDecimal("21")));
        assertEquals(Convert.toWei("21", Convert.Unit.KWEI), (new BigDecimal("21000")));
        assertEquals(Convert.toWei("21", Convert.Unit.MWEI), (new BigDecimal("21000000")));
        assertEquals(Convert.toWei("21", Convert.Unit.GWEI), (new BigDecimal("21000000000")));
        assertEquals(Convert.toWei("21", Convert.Unit.SZABO), (new BigDecimal("21000000000000")));
        assertEquals(
                Convert.toWei("21", Convert.Unit.FINNEY), (new BigDecimal("21000000000000000")));
        assertEquals(
                Convert.toWei("21", Convert.Unit.ETHER), (new BigDecimal("21000000000000000000")));
        assertEquals(
                Convert.toWei("21", Convert.Unit.KETHER),
                (new BigDecimal("21000000000000000000000")));
        assertEquals(
                Convert.toWei("21", Convert.Unit.METHER),
                (new BigDecimal("21000000000000000000000000")));
        assertEquals(
                Convert.toWei("21", Convert.Unit.GETHER),
                (new BigDecimal("21000000000000000000000000000")));
    }