How to get all the video galleries as a VideoGalleryCollection?

I need to get all the VideoGallery Videos (EPiServer.Community.VideoGallery.Video).

I have tried to get them as below,

EPiServer.Community.VideoGallery.GetVideos(...)

However, it requires a VideoGalleryCollection as an argument.

Any way to get all the video galleries as VideoGalleryCollection? (So I could use the above GetVideos(..) to get videos)