void (@NotNull List<? extends VirtualFile> roots, @NotNull ArrayList<? super AbstractTreeNode<?>> children, @NotNull TodoTreeBuilder builder) { final PsiManager psiManager = PsiManager.getInstance(myProject); for (VirtualFile dir : roots) { final PsiDirectory directory = psiManager.findDirectory(dir); if (directory == null) { continue; } final Iterator<PsiFile> files = builder.getFiles(directory); if (!files.hasNext()) continue; TodoDirNode dirNode = new TodoDirNode(myProject, directory, builder); if (!children.contains(dirNode)) { children.add(dirNode); } } }