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12.15.2 Folder Objects

`Folder` instances represent open folders and have the following methods:

`error`(format[, ...])
  Print an error message - can be overridden.

`getfullname`()
  Return the folder's full pathname.

`getsequencesfilename`()
  Return the full pathname of the folder's sequences file.

`getmessagefilename`(n)
  Return the full pathname of message n of the folder.

`listmessages`()
  Return a list of messages in the folder (as numbers).

`getcurrent`()
  Return the current message number.

`setcurrent`(n)
  Set the current message number to n.

`parsesequence`(seq)
  Parse msgs syntax into list of messages.

`getlast`()
  Get last message, or `0` if no messages are in the folder.

`setlast`(n)
  Set last message (internal use only).

`getsequences`()
  Return dictionary of sequences in folder. The sequence names are used as keys, and the values are the lists of message numbers in the sequences.

`putsequences`(dict)
  Return dictionary of sequences in folder name: list.

`removemessages`(list)
  Remove messages in list from folder.

`refilemessages`(list, tofolder)
  Move messages in list to other folder.

`movemessage`(n, tofolder, ton)
  Move one message to a given destination in another folder.

`copymessage`(n, tofolder, ton)
  Copy one message to a given destination in another folder.