@Nullable
  private static PsiVariable getFileVariable(@NotNull PsiMethodCallExpression call) {
    PsiElement qualifier = call.getMethodExpression().getQualifier();
    if (qualifier instanceof PsiParenthesizedExpression) {
      qualifier = PsiUtil.skipParenthesizedExprDown((PsiExpression)qualifier);
    }
    PsiReferenceExpression ref = ObjectUtils.tryCast(qualifier, PsiReferenceExpression.class);
    if (ref == null) return null;
    return ObjectUtils.tryCast(ref.resolve(), PsiVariable.class);
  }
@Nullable
  private static PsiVariable getFileVariable(@NotNull PsiMethodCallExpression call)