Update SMART stats using the input method.

def update(self):
        """Update SMART stats using the input method."""
        # Init new stats
        stats = self.get_init_value()

        if import_error_tag:
            return self.stats

        if self.input_method == 'local':
            stats = get_smart_data()
        elif self.input_method == 'snmp':
            pass

        # Update the stats
        self.stats = stats

        return self.stats