> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. ## 2.15.1 **`(fix):`** The unchecked base model no longer coerces None to a type. ### What's been fixed * The unchecked base model no longer coerces None to a type. * The http client appropriately defaults empty fields within RequestOptions.