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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_direct_band_gap(self):
 """ Returns the direct band gap. Returns: the value of the direct band gap """

        if self.is_metal():
            return 0.0
        dg = self.get_direct_band_gap_dict()
        return min(v['value'] for v in dg.values())