Access checks are currently tied to a "file system entry". As of #96, a "file system entry" now corresponds to an actual file or directory on disk. We need to support access checks on FileSystemHandles which don't correspond to an entry (e.g. the entry has been removed), so the access checks must be tied to something else.

We could tie access checks to a FileSystemHandle or a "file system locator". See #96 (comment)