pub fn unsupported_async(ctx: &RequestCtx<'_>) -> Option<&'static str>Expand description
Why a mutation cannot be honored in async mode, if it cannot, a short,
value-free reason for the 400. These all need read-modify-write against the
document’s current state, which does not exist at enqueue time, so async
rejects them rather than silently mis-applying or dropping the precondition.