human
Solve the following python programming problem given the following code:
@ contextmanager 
def SetEnvironmentForTest(env_variable_dict) : 
    'Sets OS environment variables for a single test.' 
    def _ApplyDictToEnvironment(dict_to_apply) : 
        for (k, v) in dict_to_apply.iteritems () : 
            old_values [k] = os.environ.get (k) 
            if (v is not None) : 
                os.environ [k] = v 
else : 
                if (k in os.environ) : 
                    del os.environ [k] 
old_values = { 
        
} 
    for k in _ApplyDictToEnvironment : 
        old_values [k] = os.environ.get (k) 
try : 
        _ApplyDictToEnvironment (env_variable_dict) 
        (yield) 
finally : 
        _ApplyDictToEnvironment (old_values) 

    
    

    Fix the buggy line: for k in _ApplyDictToEnvironment :
assistant
#Here is Python program to fix the buggy line: for k in _ApplyDictToEnvironment :
.

for k in env_variable_dict :