Optional metadata type carried on each entry.
Returns the entries (files and directories) inside the given
directory node. For the root directory, parent is null.
Returns true if the given entry is a directory that can
contain children (even if currently empty).
Datasource contract for the file browser.
Implementations may back this with an in-memory tree, a REST API, IndexedDB, or any other storage mechanism. All methods may return either a synchronous value or a
Promise.