public static void visitRoots(@NotNull final PsiElement elt, @NotNull final RootVisitor visitor) {
    // real search
    final Module module = ModuleUtilCore.findModuleForPsiElement(elt);
    if (module != null) {
      visitRoots(module, false, visitor);
    }
    else {
      if (PythonRuntimeService.getInstance().isInScratchFile(elt)) {
        visitRootsInAllModules(elt.getProject(), visitor);
      }
      final PsiFile containingFile = elt.getContainingFile();
      if (containingFile != null) {
        visitSdkRoots(containingFile, visitor);
      }
    }
  }
public static void visitRoots(@NotNull final PsiElement elt, @NotNull final RootVisitor visitor)