human
Solve the following python programming problem given the following code:
def build_report_callback(self, url) : 
    def on_report(data) : 
        if (data is None) : 
            return 
self.log (logging.CRITICAL, ("SSLStrip'd URL %s was visited!" % url)) 
        self.log_event (logging.CRITICAL, connection.AttackEvent (self.connection, self.name, True, url)) 
        self.connection.vuln_notify (util.vuln.VULN_SSL_STRIP) 
        return False 
return url 

    
    

    Fix the buggy line: return url
assistant
#Here is Python program to fix the buggy line: return url
.

return def on_report(