what is :(){ :|:& };: command?

in tk.Button(self.frame, text = text, command= lambda:self.new_window(number, _class)).grid(padx= 5, pady= 5, sticky= N + E + W + S) File "C:\Users\CSB\Desktop\python program\triple_window.py", line 50, in new_window

Add your SSH private key to the ssh-agent. If you created your key with a different name, or if you are adding an existing key that has a different name, replace id_rsa in the command with the name of your private key file.