### Question:
EnsResolver { public static boolean isValidEnsName(String input) { return input != null && (input.contains(".") || !WalletUtils.isValidAddress(input)); } EnsResolver(Web3j web3j, long syncThreshold);  EnsResolver(Web3j web3j); void setSyncThreshold(long syncThreshold); long getSyncThreshold(); PublicResolver obtainPublicResolver(String ensName); String resolve(String contractId); String reverseResolve(String address); static boolean isValidEnsName(String input);  }### Answer:
@Test public void testIsEnsName() { assertTrue(isValidEnsName("eth")); assertTrue(isValidEnsName("web3.eth")); assertTrue(isValidEnsName("0x19e03255f667bdfd50a32722df860b1eeaf4d635.eth")); assertFalse(isValidEnsName("0x19e03255f667bdfd50a32722df860b1eeaf4d635")); assertFalse(isValidEnsName("19e03255f667bdfd50a32722df860b1eeaf4d635")); assertTrue(isValidEnsName("")); }