ModelIO macOS xcode14.0 beta1

#ModelIO.framework https://github.com/xamarin/xamarin-macios/pull/15715

diff -ruN /Applications/Xcode_13.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLObject.h /Applications/Xcode_14.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLObject.h
--- /Applications/Xcode_13.3.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLObject.h	2022-02-23 07:59:27.000000000 -0500
+++ /Applications/Xcode_14.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLObject.h	2022-06-03 18:09:19.000000000 -0400
@@ -117,7 +117,7 @@
 /*!
  @property children
  @abstract Short hand property for the MDLObjectContainerComponent.
- @discussion The default value is nil
+ @discussion The default value is an empty MDLObjectContainer 
  
  @see MDLObjectContainerComponent
  */