human
Solve the following python programming problem given the following code:
@ classmethod 
def convert_to_requested_unit_applier(cls, compatibles) : 
    def apply_requested_unit(target, _graph_config) : 
        tags = target ['tags'] 
        try : 
            (scale, extra_op) = compatibles [tags ['unit']] 
except (KeyError, ValueError) : 
            warnings.warn (("Found a target with unit %r which wasn't in our list of compatible units (%r) for this query." % (tags.get ('unit'), compatibles.keys ())), RuntimeWarning) 
            return 
if (extra_op == 'derive') : 
            cls.apply_derivative_to_target (target, scale) 
else : 
            if (scale != 1.0) : 
                cls.apply_graphite_function_to_target (target, 'scale', scale) 
if (extra_op == 'integrate') : 
                cls.apply_graphite_function_to_target (target, 'hitcount', '1min') 
                cls.apply_graphite_function_to_target (target, 'integral') 
return cls 

    
    

    Fix the buggy line: return cls
assistant
#Here is Python code to fix the buggy line: return cls
.

return def apply_requested_unit(