code: public static void addDeprecations(DeprecationDelta[] deltas) {
  		DeprecationContext prev, next;
  		do {
  			prev = deprecationContext.get();
  			next = new DeprecationContext(prev, deltas);
  		} while (!deprecationContext.compareAndSet(prev, next));
  	}
docs: Adds a set of deprecated keys to the global deprecations.
  
  This method is lockless.  It works by means of creating a new
  DeprecationContext based on the old one, and then atomically swapping in
  the new context.  If someone else updated the context in between us reading
  the old context and swapping in the new one, we try again until we win the
  race.
  
  @param deltas   The deprecations to add.