AttributeCollection's IsEmpty will alway be false

Description

The IsEmpty property in AttributeCollection will always be false, because the _data is never been null

As the Constructor code says, we will set the _data field a not null value

https://github.com/OfficeDev/Open-XML-SDK/blob/0977a9430407115ff9ed149f60496fbb2688b5e5/src/DocumentFormat.OpenXml/Framework/Metadata/AttributeCollection.cs#L15-L27

And the IsEmpty property will be false only when the _data is null

https://github.com/OfficeDev/Open-XML-SDK/blob/0977a9430407115ff9ed149f60496fbb2688b5e5/src/DocumentFormat.OpenXml/Framework/Metadata/AttributeCollection.cs#L29

[lindexi]

@twsouthwick Thank you. It is not null.

Why it is not null? Because we use the DocumentFormat.OpenXml.Framework.ReadOnlyArray to cast the null array to ReadOnlyArray object.

    public static implicit operator ReadOnlyArray<T>(T[] array) => new ReadOnlyArray<T>(array);

That means the ElementMetadata will never receive the null attributes argument

[twsouthwick]

Do you have a repro of a null red? The readonly array is a custom type that gracefully handles null. If you have a repro, that would be very helpful.