Mediaplayer playlist media_content_type extra keys not allowed

According to the documentation of media player the media_content_id and the media_content_type are not optional in media_player.play_media, so I think I need both.

Therefore in my automation I added both:

alias: PlaylistPaul
description: play my playlist
triggers: []
conditions: []
actions:
  - action: media_player.media_play
    metadata: {}
    target:
      entity_id: media_player.c700_v2_0406
    data:
      media_content_type: playlist
      media_content_id: Paul
mode: single

However I get the following error when running the automation:

Logger: homeassistant.components.automation.playlistpaul
Source: components/automation/__init__.py:764
integration: Automation (documentation, issues)
First occurred: 10:01:58 (1 occurrences)
Last logged: 10:01:58

Error while executing automation automation.playlistpaul: extra keys not allowed @ data['media_content_type']

My question is, is this a bug of media player, the documentation of media player or is this a bug of the integration of my specific player (Bluesound). Or have I done something wrong in my automation?