def publish(data, interval)
      raise ArgumentError, "data too long" if data.bytesize > MAX_BEACON_DATA
      @actor.send_picture("sbi", :string, "PUBLISH", :string, data,
                              :int, data.bytesize, :int, interval)
    end
def publish(data, interval)
      raise ArgumentError, "data too long" if data.bytesize > MAX_BEACON_DATA
      @actor.send_picture("sbi", :string, "PUBLISH", :string, data,
                              :int, data.bytesize, :int, interval)
    end
Start broadcasting a beacon.
 @param data [String] data to publish
 @param interval [Integer] interval in msec
 @raise [ArgumentError] if data is longer than {MAX_BEACON_DATA} bytes
 @return [void]