Replace Arc<Box<dyn Scheme>> with Arc<dyn Scheme>.
Removes one level of indirection, by replacing the type of the entries in the scheme BTreeMap, from Arc<Box<dyn Scheme + Send + Sync>> with Arc<dyn Scheme + Send + Sync.
Removes one level of indirection, by replacing the type of the entries in the scheme BTreeMap, from Arc<Box<dyn Scheme + Send + Sync>> with Arc<dyn Scheme + Send + Sync.
merged
mentioned in commit 5d4aa751