From e52f413597c224d636206022b1c4bbb677973554 Mon Sep 17 00:00:00 2001
From: dahall <dahall@byu.net>
Date: Wed, 12 Feb 2020 20:35:33 -0700
Subject: [PATCH] Added paramter attributes

---
 PInvoke/Shell32/ShObjIdl.INamespaceTreeControl.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/PInvoke/Shell32/ShObjIdl.INamespaceTreeControl.cs b/PInvoke/Shell32/ShObjIdl.INamespaceTreeControl.cs
index b41231aa..df040695 100644
--- a/PInvoke/Shell32/ShObjIdl.INamespaceTreeControl.cs
+++ b/PInvoke/Shell32/ShObjIdl.INamespaceTreeControl.cs
@@ -615,7 +615,7 @@ namespace Vanara.PInvoke
 			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-inamespacetreecontrol-insertroot HRESULT
 			// InsertRoot( int iIndex, IShellItem *psiRoot, SHCONTF grfEnumFlags, NSTCROOTSTYLE grfRootStyle, IShellItemFilter *pif );
 			[PreserveSig]
-			HRESULT InsertRoot(int iIndex, IShellItem psiRoot, SHCONTF grfEnumFlags, NSTCROOTSTYLE grfRootStyle, [In] IShellItemFilter pif);
+			HRESULT InsertRoot(int iIndex, IShellItem psiRoot, SHCONTF grfEnumFlags, NSTCROOTSTYLE grfRootStyle, [In, Optional] IShellItemFilter pif);
 
 			/// <summary>Removes a root and its children from a tree.</summary>
 			/// <param name="psiRoot">