public BigDecimal toBtc() {
        return satoshiToBtc(this.value);
    }
@Test
    public void testToBtc() {
        assertThat(new BigDecimal("-92233720368.54775808"),  Matchers.comparesEqualTo(Coin.valueOf(Long.MIN_VALUE).toBtc()));
        assertThat(new BigDecimal("-0.00000001"), Matchers.comparesEqualTo(NEGATIVE_SATOSHI.toBtc()));
        assertThat(BigDecimal.ZERO, Matchers.comparesEqualTo(ZERO.toBtc()));
        assertThat(new BigDecimal("0.00000001"), Matchers.comparesEqualTo(SATOSHI.toBtc()));
        assertThat(BigDecimal.ONE,  Matchers.comparesEqualTo(COIN.toBtc()));
        assertThat(new BigDecimal(50),  Matchers.comparesEqualTo(FIFTY_COINS.toBtc()));
        assertThat(new BigDecimal("92233720368.54775807"),  Matchers.comparesEqualTo(Coin.valueOf(Long.MAX_VALUE).toBtc()));
    }