docs: protected List<ScopeImpl> collectNonExistingFlowScopes(ScopeImpl scope, final MigratingScopeInstanceBranch migratingExecutionBranch) {
      FlowScopeWalker walker = new FlowScopeWalker(scope);
      final List<ScopeImpl> result = new LinkedList<ScopeImpl>();
      walker.addPreVisitor(new TreeVisitor<ScopeImpl>() {
  
        @Override
        public void visit(ScopeImpl obj) {
          result.add(0, obj);
        }
      });
  
      walker.walkWhile(new ReferenceWalker.WalkCondition<ScopeImpl>() {
  
        @Override
        public boolean isFulfilled(ScopeImpl element) {
          return migratingExecutionBranch.hasInstance(element);
        }
      });
  
      return result;
    }