def METHOD_NAME(self, **kwargs):
    try:
        return kwargs.get(self.resource_group_parameter_name)
    except KeyError:
        template = (
            "To create a storage account a resource group is required. Please add "
            "decorator @{} in front of this storage account preparer."
        )
        raise AzureTestError(template.format(ResourceGroupPreparer.__name__))