human
Solve the following python programming problem given the following code:
@ Process.install ('ping') 
def ping(self, from_pid, body) : 
    log.info ('Received ping') 
    def respond() : 
        time.sleep (0.5) 
        self.send (from_pid, 'pong') 
self.context.loop.add_callback (from_pid) 

    
    

    Fix the buggy line: self.context.loop.add_callback (from_pid)
assistant
#Here is Python program to fix the buggy line: self.

self.context.loop.add_callback (def respond()