There is a command group 'az_eventgrid_namespace_client'. This group of commands could 'manage eventgrid namespace client'. 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_eventgrid_namespace_client_create'.The syntax is: az eventgrid namespace client create --client-name
                                     --namespace-name
                                     --resource-group
                                     [--attributes]
                                     [--authentication]
                                     [--authentication-name]
                                     [--client-certificate-authentication]
                                     [--description]
                                     [--no-wait {0, 1, f, false, n, no, t, true, y, yes}]
                                     [--state {disabled, enabled}]. The 1th example of the child command would be to use it to 'create client', the syntax is: az eventgrid namespace client create -g rg --namespace-name name -n client-name  --attributes "{'room':'345','floor':5}" --client-certificate-authentication "{validationScheme:SubjectMatchesAuthenticationName}". The parameter '--client-name --name -n' is required. It is used to the client name.. The parameter '--namespace-name' is required. It is used to name of the namespace.. The parameter '--resource-group -g' is required. It is used to name of resource group. you can configure the default group using `az configure --defaults group=<name>`.. The parameter '--attributes' is optional. attributes for the client.  support json-file and yaml-file.. The parameter '--authentication' is optional. authentication information for the client.  support shorthand-syntax, json-file and yaml-file. try "??" to show more.. The parameter '--authentication-name' is optional. the name presented by the client for authentication. the default value is the name of the resource.. The parameter '--client-certificate-authentication' is optional. the client certificate authentication information.  support shorthand-syntax, json-file and yaml-file. try "??" to show more.. The parameter '--description' is optional. description for the client resource.. The parameter '--no-wait' is optional. do not wait for the long-running operation to finish.. The parameter '--state' is optional. indicates if the client is enabled or not. default value is enabled.. 