code: private void sendBlob(String index, byte[] blob) {
  
          // Send "blob" containing provided data
          sendInstruction(new GuacamoleInstruction("blob", index,
             BaseEncoding.base64().encode(blob)));
  
      }
docs: Injects a "blob" instruction into the outbound Guacamole protocol
  stream, as if sent by the connected client. "blob" instructions are used
  to send chunks of data along a stream.
  
  @param index
  The index of the stream that this "blob" instruction relates to.
  
  @param blob
  The chunk of data to send within the "blob" instruction.