Update Wifi stats using the input method.

        Stats is a list of dict (one dict per hotspot)

        :returns: list -- Stats is a list of dict (hotspot)

def update(self):
        """Update Wifi stats using the input method.

        Stats is a list of dict (one dict per hotspot)

        :returns: list -- Stats is a list of dict (hotspot)
        """
        # Init new stats
        stats = self.get_init_value()

        # Exist if we can not grab the stats
        if import_error_tag:
            return stats

        if self.input_method == 'local':
            # Update stats using the standard system lib

            # Grab network interface stat using the psutil net_io_counter method
            try:
                netiocounters = psutil.net_io_counters(pernic=True)
            except UnicodeDecodeError:
                return stats

            for net in netiocounters:
                # Do not take hidden interface into account
                if self.is_hide(net):
                    continue

                # Grab the stats using the Wifi Python lib
                try:
                    wifi_cells = Cell.all(net)
                except InterfaceError as e:
                    # Not a Wifi interface
                    logger.debug("WIFI plugin: Scan InterfaceError ({})".format(e))
                    pass
                except Exception as e:
                    # Other error
                    logger.debug("WIFI plugin: Can not grab cellule stats ({})".format(e))
                    pass
                else:
                    for wifi_cell in wifi_cells:
                        hotspot = {
                            'key': self.get_key(),
                            'ssid': wifi_cell.ssid,
                            'signal': wifi_cell.signal,
                            'quality': wifi_cell.quality,
                            'encrypted': wifi_cell.encrypted,
                            'encryption_type': wifi_cell.encryption_type if wifi_cell.encrypted else None
                        }
                        # Add the hotspot to the list
                        stats.append(hotspot)

        elif self.input_method == 'snmp':
            # Update stats using SNMP

            # Not implemented yet
            pass

        # Update the stats
        self.stats = stats

        return self.stats