Method try_downcast_from

crates/vm/src/builtins/str.rs:2040–2043

(obj: &PyObject, vm: &VirtualMachine)

    }

    fn try_downcast_from(obj: &PyObject, vm: &VirtualMachine) -> PyResult<()> {
        let str = obj.try_downcast_ref::<PyStr>(vm)?;
        str.ensure_valid_utf8(vm)
    }
}

impl<'a> From<&'a AsciiStr> for PyUtf8Str {