human
Solve the following python programming problem given the following code:
def requires_dep(lib) : 
    'Decorator for functions that require a supported third-party library.' 
    def decorator(f) : 
        @ functools.wraps (f) 
        def wrapper(* args, **kwargs) : 
            dep = OPTIONAL_DEPS [lib] 
            if (not dep) : 
                raise_dep_error (lib) 
return f (* args, ** kwargs) 
return wrapper 
return lib 

    
    

    Fix the buggy line: return lib
assistant
#Here is Python program to fix the buggy line: return lib
.

return def decorator(