missing attribute on the ResourceBackedMetadataProvider type

[Tom Scavo]

The documentation [1] claims that the following attribute exists:

MetadataProvider[@xsi:type="ResourceBackedMetadataProvider"]/@resourceRef

but AFAICT this attribute is not defined by the schema. What am I missing?

Thanks,

Tom

[1] https://wiki.shibboleth.net/confluence/x/CAMnAQ