### Question:
HdKeyPath implements Serializable { public HdKeyPath getChild(String path){ Iterator<String> iterator = Splitter.on("/").split(path).iterator(); return this.getChild(iterator); } HdKeyPath(HdKeyPath parent, UnsignedInteger index,boolean hardened); private  HdKeyPath(); static HdKeyPath valueOf(String path); HdKeyPath getChild(String path); @SuppressWarnings("unchecked") Optional<T> findPartOf(Class<T> ofClass); boolean isHardened(); HdKeyPath getNonHardenedChild(int index); HdKeyPath getHardenedChild(int index); Bip44Purpose getBip44Purpose(); List<Integer> getAddressN(); @Override String toString(); @Override boolean equals(Object o); @Override int hashCode(); int getLastRawIndex(); int getLastIndex(); static final String HARDENED_MARKER; static final HdKeyPath ROOT; static final Bip44Purpose BIP44; static final HdKeyPath BIP32_ROOT; static final Bip44CoinType BIP44_TESTNET; static final Bip44CoinType BIP44_PRODNET; }### Answer:
@Test public void testGetChild() throws Exception { HdKeyPath t1 = HdKeyPath.valueOf("m/44'/0'/1'/0/3"); assertTrue( t1 instanceof Bip44Address ); assertTrue( !((Bip44Address) t1).isTestnet() ); assertTrue( ((Bip44Address) t1).isExternal() ); assertTrue(!t1.isHardened()); HdKeyPath t2 = HdKeyPath.valueOf("m/44'/1'/0'/1/3"); assertTrue( t2 instanceof Bip44Address ); assertTrue( ((Bip44Address) t2).isTestnet() ); assertTrue( !((Bip44Address) t2).isExternal() ); HdKeyPath t3 = HdKeyPath .BIP44 .getCoinTypeBitcoin() .getAccount(UnsignedInteger.valueOf(0)) .getInternalChain() .getAddress(UnsignedInteger.valueOf(5)); assertTrue(t3 != null); assertTrue( !((Bip44Address) t3).isExternal()); assertTrue( !((Bip44Address) t3).isTestnet()); }