filter_folder
Description:
public int filter_folder (Folder folder, UIDCache cache, GenericArray<string>? uids, bool remove, Cancellable? cancellable = null) throws Error
  
  Filters a folder based on rules defined in the FilterDriver object.
Parameters:
| this | CamelFilterDriver | 
| folder | CamelFolder to be filtered | 
| cache | UID cache (needed for POP folders) | 
| uids | message uids to be filtered or null (as a shortcut to filter all messages) | 
| remove | TRUE to mark filtered messages as deleted | 
| cancellable | optional Cancellable object, or null | 
Returns:
| -1 if errors were encountered during filtering, otherwise returns 0. |