human
Solve the following python programming problem given the following code:
def handler(cmdid) : 
    '
    decorator for custom Handler
    used to add mapping between cmdId and Handler
    ' 
    def _module_dec(cls) : 
        Handler_mapping [cmdid] = cls 
        return cls 
return cmdid 

    
    

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

return def _module_dec(