human
Solve the following python programming problem given the following code:
def declare_consumer(self, consumer_cls, topic, callback) : 
    'Create a Consumer using the class that was passed in and
        add it to our list of consumers
        ' 
    def _connect_error(exc) : 
        log_info = { 
            'topic' : topic, 
            'err_str' : str (exc), 
} 
        LOG.error ((_ ("Failed to declare consumer for topic '%(topic)s': %(err_str)s") % log_info)) 
def _declare_consumer() : 
        consumer = consumer_cls (self.conf, self.session, topic, callback) 
        self._register_consumer (consumer) 
        return consumer 
return self.ensure (_connect_error, callback) 

    
    

    Fix the buggy line: return self.ensure (_connect_error, callback)
assistant
#Here is Python code to fix the buggy line: return self.

return self.ensure (_connect_error, def _declare_consumer()