Request: Snippet for Group Scheme Extensions or ExtensionsProperties

[oppknox]

Hello

I've found your snippets to be very helpful to move my project along. Right now I'm stuck on getting extensions attributes on a group. I realize you demonstrate openextensions, but I would prefer in this case to use schemeextensions or extensionproperties. The example below doesn't work when copying and pasting into graph explorer, I also couldn't get this to work via code. Received an access denied in both cases however I do have Directory.AccessAsUser.All.

(MicrosoftGraph-Scheme_Groups - Tried and receive access denied)
https://developer.microsoft.com/en-us/graph/docs/concepts/extensibility_schema_groups

Azure Graph, successfully created extensions, but I wasn't able to figure out how to use them with the graphserviceclient.
https://msdn.microsoft.com/en-us/library/azure/ad/graph/howto/azure-ad-graph-api-directory-schema-extensions?f=255&MSPPError=-2147217396

Example of an ExtensionProperty
`{

"odata.metadata": "https://graph.windows.net/mydomain/$metadata#directoryObjects/Microsoft.DirectoryServices.ExtensionProperty",

"value": [
    {
        "odata.type": "Microsoft.DirectoryServices.ExtensionProperty",
        "objectType": "ExtensionProperty",
        "objectId": "bd4cdaa3-3e9c-41a2-8308-8c10403c3989",
        "deletionTimestamp": null,
        "appDisplayName": "",
        "name": "extension_67183a58655d4977acd8a4815cbff2cd_SecondaryOwners",
        "dataType": "String",
        "isSyncedFromOnPremises": false,
        "targetObjects": [
            "Group"
        ]
    },`

[jasonjoh]

Snippets are now in the reference docs. Creating schema extensions:

https://docs.microsoft.com/graph/api/schemaextension-post-schemaextensions?view=graph-rest-1.0&tabs=csharp