### Question:
TransactionUtils { public static String generateTransactionHashHexEncoded( RawTransaction rawTransaction, Credentials credentials) { return Numeric.toHexString(generateTransactionHash(rawTransaction, credentials)); }  static byte[] generateTransactionHash(
            RawTransaction rawTransaction, Credentials credentials); static byte[] generateTransactionHash(
            RawTransaction rawTransaction, byte chainId, Credentials credentials); static String generateTransactionHashHexEncoded(
            RawTransaction rawTransaction, Credentials credentials); static String generateTransactionHashHexEncoded(
            RawTransaction rawTransaction, byte chainId, Credentials credentials);  }### Answer:
@Test public void testGenerateEip155TransactionHash() { assertThat(generateTransactionHashHexEncoded( TransactionEncoderTest.createContractTransaction(), (byte) 1, SampleKeys.CREDENTIALS), is("0x62140b583dc4421fbdda95157fd8e3737588e7f7ede321f85ce9565199d3be89")); }
@Test public void testGenerateEip155TransactionHash() { assertThat(generateTransactionHashHexEncoded( TransactionEncoderTest.createContractTransaction(), (byte) 1, SampleKeys.CREDENTIALS), is("0x568c7f6920c1cee8332e245c473657b9c53044eb96ed7532f5550f1139861e9e")); }
@Test public void testGenerateEip155TransactionHash() { assertEquals( generateTransactionHashHexEncoded( TransactionEncoderTest.createContractTransaction(), (byte) 1, SampleKeys.CREDENTIALS), ("0x568c7f6920c1cee8332e245c473657b9c53044eb96ed7532f5550f1139861e9e")); }