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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 label_total_duration(self):
 """ Return for each distinct label value the total duration of all occurrences. Returns: dict: A dictionary containing for every label-value (key) the total duration in seconds (value). Example: {'a': 7.5 'b': 7.0} """


        durations = collections.defaultdict(float)

        for label in self:
            durations[label.value] += label.duration

        return durations