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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 get_total_term_frequency(self, term):
 """ Gets the frequency of the specified term in the entire corpus added to the HashedIndex. """

        if term not in self._terms:
            raise IndexError(TERM_DOES_NOT_EXIST)

        return sum(self._terms[term].values())