title: How to make signalEnumerator(for: identifier) call the relevant enumerateChanges method
body: <p>In macOS FileProvider extension, when I invoke:</p>
  <pre><code>manager.signalEnumerator(for: identifier) { error in
      print(&quot;Signal completed with error: \(error)&quot;)
  }
  </code></pre>
  <p>where <code>identifier</code> is identifier of the relevant folder which contains remote changes, system does NOT call the <code>enumerateChanges</code> method on relevant <code>FileProviderEnumerator</code>.</p>
  <p>On other hand if I invoke</p>
  <pre><code>manager.signalEnumerator(for: .workingSet) { error in
      print(&quot;Signal completed with error: \(error)&quot;)
  }
  </code></pre>
  <p>there the system properly calls the relevant <code>enumerateChanges</code> method.</p>
  <p>Is there a way to make sure that <code>enumerateChanges</code> will be invoked for the provided <code>itemIdentifier</code>? Or is there some explanation as to why the system doesn't call the <code>enumerateChanges</code> method when I provide folder item identifier?</p>