The ID of the asset. This should be unique amongst all assets with the same #GESAsset:extractable-type. Depending on the associated #GESExtractable implementation, this id may convey some information about the #GObject that should be extracted. Note that, as such, the ID will have an expected format, and you can not choose this value arbitrarily. By default, this will be set to the type name of the #GESAsset:extractable-type, but you should check the documentation of the extractable type to see whether they differ from the default behaviour.
The default proxy for this asset, or %NULL if it has no proxy. A proxy will act as a substitute for the original asset when the original is requested (see ges_asset_request()).
Setting this property will not usually remove the existing proxy, but will replace it as the default (see ges_asset_set_proxy()).
The #GESExtractable object type that can be extracted from the asset.