human
Solve the following python programming problem given the following code:
@ classmethod 
def encode(cls, attributes) : 
    def _encode(atype, payload) : 
        def pad(length, to = 4) : 
            return (((length + to) - 1) & (~ (to - 1))) 
length = (cls.Header.LEN + len (payload)) 
        raw = (pack (cls.Header.PACK, length, atype) + payload) 
        pad = (pad (length) - len (raw)) 
        if pad : 
            raw += ('\x00' * pad) 
return raw 
return ''.join ([_encode (_encode, v) for (k, v) in attributes.items ()]) 

    
    

    Fix the buggy line: return ''.join ([_encode (_encode, v) for (k, v) in attributes.items ()])
assistant
#Here is Python code to fix the buggy line: return ''.

return ''.join ([_encode (k, v) for (k, v) in attributes.items ()])