### Question:
SigningKey { public byte[] toBytes() { return seed; } SigningKey(byte[] seed);  SigningKey();  SigningKey(String seed, Encoder encoder); VerifyKey getVerifyKey(); byte[] sign(byte[] message); String sign(String message, Encoder encoder); byte[] toBytes(); @Override String toString();  }### Answer:
@Test public void testCreateByteValidKey() throws Exception { try { new SigningKey(SIGN_PRIVATE, HEX).toBytes(); } catch (Exception e) { e.printStackTrace(); fail("Should return a valid key size"); } }
@Test public void testSerializesToBytes() throws Exception { try { byte[] rawKey = HEX.decode(SIGN_PRIVATE); SigningKey key = new SigningKey(SIGN_PRIVATE, HEX); assertTrue("Correct sign key expected", Arrays.equals(rawKey, key.toBytes())); } catch (Exception e) { fail("Should return a valid key size"); } }