Right now, the FakeLogRecord exposes the StructuredState property that returns the record's set of name/value pairs. This is not particularly convenient for tests that want to probe whether a record contains a particular tag with a particular value.

FakeLogRecord could expose a dictionary to make test code easier to write. Alternatively, instead of expose a dictionary, it could expose a MatchTag(string tagName, object? tagValue) method that test code can assert on.