apollo-core/src/main/java/com/ctrip/framework/foundation/internals/io/ByteOrderMark.java/ByteOrderMark/getBytes
class ByteOrderMark:  public byte[] getBytes() {
    final byte[] copy = new byte[bytes.length];
    for (int i = 0; i < bytes.length; i++) {
      copy[i] = (byte) bytes[i];
    }
    return copy;
  }