<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def update(self, d):
 """Update the dict with the dict tree in parameter d. Parameters d : dict New dict content """


        # Call __setitem__ for all keys in d
        for key in list(d.keys()):
            self.__setitem__(key, d[key])