User patch (remove) request in sample does not verify schema for required attributes

[noorez]

https://github.com/AzureAD/SCIMReferenceCode/blob/12f21fbe90a09cc7acf8f834da73f482e3af9a34/Microsoft.SCIM.WebHostSample/Provider/InMemoryUserProvider.cs#L331

I noticed in the sample schema, that the userName attribute (as well as I believe in the SCIM specifications..) that the userName attribute is required, however, it (the remove Patch request) does not verify this. Where is the appropriate place to check these requirements?

Should it be in the base library code that has been provided (by querying the schema identifier stored in IProvider.Schema) or should it be done directly in the individual IProvider implementations?..