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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:
 async def _send_scan_event(self, device):
 """Send a scan event from a device."""


        conn_string = str(device.iotile_id)
        info = {
            'connection_string': conn_string,
            'uuid': device.iotile_id,
            'signal_strength': 100,
            'validity_period': self.ExpirationTime
        }

        await self.notify_event(conn_string, 'device_seen', info)