TODO

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#      Missing portals      #
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* Background portal
  - a portal for autostart of applications, or to notify users that an application
    was started in background

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#     Missing functions     #
#############################

* Inhibit portal
  - CreateMonitor
    -  creates a monitoring session. While this session is  active, the caller will
       receive StateChanged signals with updates on the session state.
  - StateChanged
    -  the StateChanged signal is sent to active monitoring sessions when the session
       state changes.
  - QueryEndResponse
    - acknowledges that the caller received the #org.freedesktop.impl.portal.Inhibit::StateChanged
      signal. This method should be called within one second or receiving a StateChanged
      signal with the 'Query End' state.

* Remote desktop portal
  - NotifyKeyboardKeysym
  - NotifyKeyboardKeycode
  - NotifyTouchDown
  - NotifyTouchMotion
  - NotifyTouchUp

* Screensharing portal
  - AvailableCursorModes
  - CreateSession - cursor_mode option
  - Window source type - ability to share windows only