code: public static byte[] addUtf8Marker(byte[] content) {
  
          if ((content != null)
              && (content.length >= 3)
              && (content[0] == UTF8_MARKER[0])
              && (content[1] == UTF8_MARKER[1])
              && (content[2] == UTF8_MARKER[2])) {
              return content;
          }
  
          if (content == null) {
              content = new byte[0];
          }
  
          byte[] ret = new byte[UTF8_MARKER.length + content.length];
  
          System.arraycopy(UTF8_MARKER, 0, ret, 0, UTF8_MARKER.length);
          System.arraycopy(content, 0, ret, UTF8_MARKER.length, content.length);
  
          return ret;
      }
docs: Adds the UTF-8 marker add the beginning of the byte array.<p>
  
  @param content the byte array where to add the UTF-8 marker
  
  @return the byte with the added UTF-8 marker at the beginning