### Question:
Base64Wrapper { public byte[] decodeB64Bytes(String encodedBytes) { byte[] result = null; if (encodedBytes != null) { result = Base64.decodeBase64(encodedBytes); } return result; }  String encodeB64Bytes(byte[] bytes); byte[] decodeB64Bytes(String encodedBytes);  }### Answer:
@Test public void testBase64Decoder() { byte[] result = wrapper.decodeB64Bytes(encodedData); assertEquals(result, rawData); }
@Test public void testBase64DecoderNullData() { byte[] result = wrapper.decodeB64Bytes(null); assertEquals(result, null); }