human
Solve the following python programming problem given the following code:
@ classmethod 
def _from_keys(self, meth, keys, chained, kw) : 
    opt = _UnboundLoad () 
    def _split_key(key) : 
        if isinstance (key, util.string_types) : 
            if (key == _WILDCARD_TOKEN) : 
                return (_DEFAULT_TOKEN,) 
else : 
                if key.startswith (('.' + _WILDCARD_TOKEN)) : 
                    key = key [1 :] 
return key.split ('.') 
else : 
            return (key,) 
all_tokens = [token for key in keys for token in _split_key (key)] 
    for token in all_tokens [0 : (- 1)] : 
        if chained : 
            opt = meth (opt, token, ** kw) 
else : 
            opt = opt.defaultload (token) 
opt._is_chain_link = True 
opt = meth (opt, _split_key [(- 1)], ** kw) 
    opt._is_chain_link = False 
    return opt 

    
    

    Fix the buggy line: opt = meth (opt, _split_key [(- 1)], ** kw)
assistant
#Here is Python code to fix the buggy line: opt = meth (opt, _split_key [(- 1)], ** kw)
.

opt = meth (opt, all_tokens [(- 1)], ** kw)