@Test
public void testToFriendlyString() {

    assertEquals("1.00 BTC", COIN.toFriendlyString());
    assertEquals("1.23 BTC", valueOf(1, 23).toFriendlyString());
    assertEquals("0.001 BTC", COIN.divide(1000).toFriendlyString());
    assertEquals("-1.23 BTC", valueOf(1, 23).negate().toFriendlyString());
}