def METHOD_NAME(cmd, namespace):  # pylint: disable=unused-argument
    # Make sure these arguments are non-empty strings.
    # When they are accidentally provided as an empty string "", they won't take effect when filtering the role
    # assignments, causing all matched role assignments to be listed/deleted. For example,
    #   az role assignment delete --assignee ""
    # removes all role assignments under the subscription.
    non_empty_args = ["assignee", "scope", "role", "resource_group_name"]
    non_empty_msg = "usage error: {} can't be an empty string. Either omit it or provide a non-empty string."
    for arg in non_empty_args:
        if getattr(namespace, arg) == "":
            # Get option name, like resource_group_name -> --resource-group
            option_name = cmd.arguments[arg].type.settings['options_list'][0]
            raise CLIError(non_empty_msg.format(option_name))
    resource_group = namespace.resource_group_name
    if namespace.scope and resource_group and getattr(resource_group, 'is_default', None):
        namespace.resource_group_name = None  # drop configured defaults