code: public Buffer toPayload() {
          /* From AppMessages.h: BL_SKETCH_META_DATA_T struct
           *
           * {
           *   PTD_UINT32 hexSize;
           *   PTD_UINT32 hexCrc;
           *   PTD_UINT32 timestamp;
           *   PTD_UINT8 hexNameSize;
           *   PTD_UINT8 hexName[MAX_SKETCH_NAME_SIZE];
           * }
           */
          Buffer buffer = new Buffer();
  
          // Pad name to 20 bytes to fill buffer completely. It will be truncated by the Bean.
          // Name has already been truncated to max length by the SketchHex constructor.
          String fullName = hexName();
          while (fullName.length() < MAX_SKETCH_NAME_LENGTH) {
              fullName += " ";
          }
  
          // !! The Bean uses little endian. Don't screw this up like I did!
          ByteOrder endian = ByteOrder.LITTLE_ENDIAN;
  
          byte[] hexSize = intToUInt32(hexSize(), endian);
          byte[] hexCrc = intToUInt32(hexCrc(), endian);
          byte[] timestamp = intToUInt32( (int) (new Date().getTime() / 1000), endian);
          byte nameLength = intToByte(hexName().length());
          ByteString name = ByteString.encodeUtf8(fullName);
  
          buffer.write(hexSize);
          buffer.write(hexCrc);
          buffer.write(timestamp);
          buffer.writeByte(nameLength);
          buffer.write(name);
  
          return buffer;
      }
docs: Get this object's metadata as a payload of bytes, ready to send to Bean in a
  {@link com.punchthrough.bean.sdk.internal.BeanMessageID#BL_CMD_START} message.
  @return The SketchMetadata in payload form