There is a command group 'az_iot_du_device_class'. This group of commands could 'device class and device class subgroup management'. The group of commands has global parameter '--debug' which means 'Increase logging verbosity to show all debug logs.'. The group of commands has global parameter '--help -h' which means 'Show this help message and exit.'. The group of commands has global parameter '--only-show-errors' which means 'Only show errors, suppressing warnings.'. The group of commands has global parameter '--output -o' which means 'Output format.'. The group of commands has global parameter '--query' which means 'JMESPath query string. See <a href="http://jmespath.org/">http://jmespath.org/</a> for more information and examples.'. The group of commands has global parameter '--subscription' which means 'Name or ID of subscription. You can configure the default subscription using `az account set -s NAME_OR_ID`.'. The group of commands has global parameter '--verbose' which means 'Increase logging verbosity. Use --debug for full debug logs.'. This group contains a child command 'az_iot_du_device_class_list'.The syntax is: az iot du device class list --account
                            --instance
                            [--filter]
                            [--gid]
                            [--resource-group]. The 1th example of the child command would be to use it to 'list device classes within an instance', the syntax is: az iot du device class list -n {account_name} -i {instance_name}. The 2th example of the child command would be to use it to 'list instance device classes filtered by friendly name', the syntax is: az iot du device class list -n {account_name} -i {instance_name} --filter "friendlyName eq 'my-favorite-class'". The 3th example of the child command would be to use it to 'list device class subgroups for the group', the syntax is: az iot du device class list -n {account_name} -i {instance_name} --group-id {device_group_id}. The 4th example of the child command would be to use it to 'list device class subgroups for the group  filtered by compatproperties manufacturer', the syntax is: az iot du device class list -n {account_name} -i {instance_name} --group-id {device_group_id} --filter "compatProperties/manufacturer eq 'Contoso'". The parameter '--account -n' is required. It is used to device update account name. you can configure the default account name using `az config set defaults.adu_account=<name>`.. The parameter '--instance -i' is required. It is used to device update instance name. you can configure the default instance name using `az config set defaults.adu_instance=<name>`.. The parameter '--filter' is optional. if provided with --group-id, supports filtering based on device class compat property names and values. for example "compatproperties/manufacturer eq 'contoso'". otherwise supports filtering by class friendly name.. The parameter '--gid --group-id' is optional. device group id. this is created from the value of the adugroup tag in the connected iot hub's device/module twin or $default for devices with no tag.. The parameter '--resource-group -g' is optional. device update account resource group name. you can configure the default group using `az config set defaults.adu_group=<name>`.. 