Function fn_approver 

pub fn fn_approver<F, Fut>(handler: F) -> Arc<dyn ToolApprover>
where
    F: Fn(&str, &Value) -> Fut + Send + Sync + 'static,
    Fut: Future<Output = ApprovalDecision> + Send + 'static,

Available on crate feature async only.

Wrap an async closure into a ToolApprover.