Using media_player/media_seek

Configuration
1

Hi,

I am trying to use the seek service but each time I call the service with this data:

Services -> Available Services -> media_player/media_seek -> Service Data -> {  "entity_id": "media_player.mpd", "seek_position": 44 }

I get:

INFO:homeassistant.core:Bus:Handling 
ERROR:homeassistant.core:BusHandler:Exception doing job
Traceback (most recent call last):
  File "/home/users/hass/lib/python3.4/site-packages/homeassistant/core.py", line 809, in job_handler
    func(arg)
  File "/home/users/hass/lib/python3.4/site-packages/homeassistant/core.py", line 663, in _execute_service
    service(call)
  File "/home/users/hass/lib/python3.4/site-packages/homeassistant/core.py", line 522, in __call__
    self.func(call)
  File "/home/users/hass/lib/python3.4/site-packages/homeassistant/components/media_player/__init__.py", line 344, in media_seek_service
    player.media_seek(position)
  File "/home/users/hass/lib/python3.4/site-packages/homeassistant/components/media_player/__init__.py", line 546, in media_seek
    raise NotImplementedError()
NotImplementedError

I am missing something or really it’s not supported by HA. Thanks you.