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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 mask_unphysical(self, data):
 """Mask data array where values are outside physically valid range."""

        if not self.valid_range:
            return data
        else:
            return np.ma.masked_outside(data, np.min(self.valid_range),
                                        np.max(self.valid_range))