Merges multiple operation handler sets into a single set. Per-operation resolution (OperationHandlerSet.getHandlerFor) composes across the children; enumerating OperationHandlerSet.handlers still forces every child.
Merges multiple operation handler sets into a single set. Per-operation resolution (OperationHandlerSet.getHandlerFor) composes across the children; enumerating OperationHandlerSet.handlers still forces every child.