public static PsiVariable @NotNull [] getVariablesVisibleAt(final @Nullable PsiElement place, String prefix) {
    if (place == null) {
      return new PsiVariable[0];
    }

    final List<PsiVariable> list = new ArrayList<>();
    VariablesProcessor varproc = new VisibleVariablesProcessor(place, prefix, list);
    PsiScopesUtil.treeWalkUp(varproc, place, null);
    return varproc.getResultsAsArray();
  }
public static PsiVariable @NotNull [] getVariablesVisibleAt(final @Nullable PsiElement place, String prefix)