human
Solve the following python programming problem given the following code:
def __init__(self, **kwargs) : 
    bad_kwargs = sorted ((set (kwargs) - set (_JOB_STEP_PARAMS))) 
    if bad_kwargs : 
        raise TypeError (('MRStep() got an unexpected keyword argument %r' % bad_kwargs [0])) 
if (not (set (kwargs) & set (_JOB_STEP_FUNC_PARAMS))) : 
        raise ValueError ('Step has no mappers and no reducers') 
self.has_explicit_mapper = any ((value for (name, value) in kwargs.items () if (name in _MAPPER_FUNCS))) 
    self.has_explicit_combiner = any ((value for (name, value) in kwargs.items () if (name in _COMBINER_FUNCS))) 
    self.has_explicit_reducer = any ((value for (name, value) in kwargs.items () if (name in _REDUCER_FUNCS))) 
    steps = dict (((f, None) for f in _JOB_STEP_PARAMS)) 
    steps.update (_check_cmd) 
    def _prefix_set(prefix) : 
        return set ((k for k in steps if (k.startswith (prefix) and steps [k]))) 
def _check_cmd(cmd, prefix_set) : 
        if ((len (prefix_set) > 1) and (cmd in prefix_set)) : 
            prefix_set.remove (cmd) 
            raise ValueError (("Can't specify both %s and %s" % (cmd, prefix_set))) 
_check_cmd ('mapper_cmd', _prefix_set ('mapper')) 
    _check_cmd ('combiner_cmd', _prefix_set ('combiner')) 
    _check_cmd ('reducer_cmd', _prefix_set ('reducer')) 
    self._steps = steps 

    
    

    Fix the buggy line: steps.update (_check_cmd)
assistant
#Here is Python code to fix the buggy line: steps.

steps.update (kwargs)