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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 discoverable(dev):
    '''
    Enable this bluetooth device to be discoverable.

    CLI Example:

    .. code-block:: bash

        salt '*' bluetooth.discoverable hci0
    '''
    if dev not in address_():
        raise CommandExecutionError(
            'Invalid dev passed to bluetooth.discoverable'
        )

    cmd = 'hciconfig {0} iscan'.format(dev)
    __salt__['cmd.run'](cmd).splitlines()
    cmd = 'hciconfig {0}'.format(dev)
    out = __salt__['cmd.run'](cmd)
    if 'UP RUNNING ISCAN' in out:
        return True
    return False