### Question:
Coin implements Monetary, Comparable<Coin>, Serializable { public String toFriendlyString() { return FRIENDLY_FORMAT.format(this).toString(); } private  Coin(final long satoshis); static Coin valueOf(final long satoshis); @Override int smallestUnitExponent(); @Override long getValue(); static Coin valueOf(final int coins, final int cents); static Coin parseCoin(final String str); static Coin parseCoinInexact(final String str); Coin add(final Coin value); Coin subtract(final Coin value); Coin multiply(final long factor); Coin divide(final long divisor); Coin[] divideAndRemainder(final long divisor); long divide(final Coin divisor); boolean isPositive(); boolean isNegative(); boolean isZero(); boolean isGreaterThan(Coin other); boolean isLessThan(Coin other); Coin shiftLeft(final int n); Coin shiftRight(final int n); @Override int signum(); Coin negate(); long longValue(); String toFriendlyString(); String toPlainString(); @Override String toString(); @Override boolean equals(final Object o); @Override int hashCode(); @Override int compareTo(final Coin other); static final int SMALLEST_UNIT_EXPONENT; static final Coin ZERO; static final Coin COIN; static final Coin CENT; static final Coin MILLICOIN; static final Coin MICROCOIN; static final Coin SATOSHI; static final Coin NEGATIVE_SATOSHI; final long value; }### Answer:
@Test public void testToFriendlyString() { assertEquals("1.00 PPC", COIN.toFriendlyString()); assertEquals("1.23 PPC", valueOf(1, 23).toFriendlyString()); assertEquals("0.001 PPC", COIN.divide(1000).toFriendlyString()); assertEquals("-1.23 PPC", valueOf(1, 23).negate().toFriendlyString()); }