human
Solve the following python programming problem given the following code:
def map_and_merge_dict_keys(fn, d) : 
    def merge_fn(* args) : 
        accumulated = set () 
        for l in args : 
            accumulated.update (l) 
return sorted (accumulated) 
output = { 
        
} 
    for (k, v) in d.iteritems () : 
        if (fn (k) not in output) : 
            output [fn (v)] = [] 
output [fn (k)].append (v) 
return dict (((f_k, merge_fn (* v)) for (f_k, v) in output.iteritems ())) 

    
    

    Fix the buggy line: output [fn (v)] = []
assistant
#Here is Python code to fix the buggy line: output [fn (v)] = []
.

output [fn (k)] = []