### Question:
RLP { public static byte[] encode(Object input) { Value val = new Value(input); if (val.isList()) { List<Object> inputArray = val.asList(); if (inputArray.isEmpty()) { return encodeLength(inputArray.size(), OFFSET_SHORT_LIST); } List<byte[]> obj = new ArrayList<>(); int length = 0; for (Object object : inputArray) { byte[] temp = encode(object); obj.add(temp); length += temp.length; } byte[] prefix = encodeLength(length, OFFSET_SHORT_LIST); byte[] output = new byte[prefix.length + length]; System.arraycopy(prefix, 0, output, 0, prefix.length); int pos = prefix.length; for (byte[] anObj : obj) { System.arraycopy(anObj, 0, output, pos, anObj.length); pos += anObj.length; } return output; } else { byte[] inputAsBytes = toBytes(input); if (inputAsBytes.length == 1 && (inputAsBytes[0] & 0xff) < 0x80) { return inputAsBytes; } else { byte[] firstByte = encodeLength(inputAsBytes.length, OFFSET_SHORT_ITEM); return concatenate(firstByte, inputAsBytes); } } }  static int decodeInt(byte[] data, int index); static BigInteger decodeBigInteger(byte[] data, int index); static RLPList decode2(byte[] msgData); static RLPElement decode2OneItem(byte[] msgData, int startPos); static DecodeResult decode(byte[] data, int pos); static byte[] encode(Object input); static byte[] encodeLength(int length, int offset); static byte[] encodeByte(byte singleByte); static byte[] encodeShort(short singleShort); static byte[] encodeInt(int singleInt); static byte[] encodeLong(long l); static byte[] encodeString(String srcString); static byte[] encodeBigInteger(BigInteger srcBigInteger); static byte[] encodeElement(byte[] srcData); static int calcElementPrefixSize(byte[] srcData); static byte[] encodeListHeader(int size); static byte[] encodeLongElementHeader(int length); static byte[] encodeList(byte[]... elements);  }### Answer:
@Test(expected = RuntimeException.class) public void testEncodeNull() { encode(null); }
@Test public void testRlpEncode() { assertEquals(result01, Hex.toHexString(RLP.encode(test01))); assertEquals(result02, Hex.toHexString(RLP.encode(test02))); assertEquals(result03, Hex.toHexString(RLP.encode(test03))); assertEquals(result04, Hex.toHexString(RLP.encode(test04))); assertEquals(result05, Hex.toHexString(RLP.encode(test05))); assertEquals(result06, Hex.toHexString(RLP.encode(test06))); assertEquals(result07, Hex.toHexString(RLP.encode(test07))); assertEquals(result08, Hex.toHexString(RLP.encode(test08))); assertEquals(result09, Hex.toHexString(RLP.encode(test09))); assertEquals(result12, Hex.toHexString(RLP.encode(test12))); assertEquals(result13, Hex.toHexString(RLP.encode(test13))); assertEquals(result16, Hex.toHexString(RLP.encode(test16))); }
@Test public void testEncode_ED() { String result = Hex.toHexString(RLP.encode(0xED)); String expected = "81ed"; assertEquals(expected, result); }