[ Version ( since = "0.11.6" ) ]
public File avatar_file { get; }
File to the latest cached avatar image, or null if this contact has no avatar, or if the
avatar data is not yet retrieved.
When avatar_token changes, this property is not updated immediately, but will be updated when the new avatar data is retrieved and stored in cache. Until then, the file will keep its old value of the latest cached avatar image.
This is set to null if AVATAR_DATA is not set
on this contact. Note that setting AVATAR_DATA will also
implicitly set AVATAR_TOKEN.