Return user data previously attached to font_face using the specified key. If no user data has been attached with the given key this function returns NULL. Since 1.0
the address of the cairo_user_data_key_t the user data was attached to
the user data previously attached or NULL.
Return user data previously attached to font_face using the specified key. If no user data has been attached with the given key this function returns NULL. Since 1.0