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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def move_items(self, from_group, to_group):
 """Take all elements from the from_group and add it to the to_group."""

        if from_group not in self.keys() or len(self.groups[from_group]) == 0:
            return

        self.groups.setdefault(to_group, list()).extend(self.groups.get
                                                        (from_group, list()))
        if from_group in self.groups:
            del self.groups[from_group]