ESP8266 DEBUG

Hello, i found a sketch while i was trying to send data to emoncms...

 sendData("AT+RST\r\n",1000,DEBUG);  
     
          sendData("AT+CWMODE=1\r\n",1000,DEBUG);

I understood all the code, but i don't know what is "1000,DEBUG" Can you explain me?

It is most likely a function that is defined in the sketch that only you can see.