##
12.18.1 MH Objects

`MH` instances have the following methods:

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

`getprofile` (key)
  Return a profile entry (`None` if not set).

`getpath` ()
  Return the mailbox pathname.

`getcontext` ()
  Return the current folder name.

`setcontext` (name)
  Set the current folder name.

`listfolders` ()
  Return a list of top-level folders.

`listallfolders` ()
  Return a list of all folders.

`listsubfolders` (name)
  Return a list of direct subfolders of the given folder.

`listallsubfolders` (name)
  Return a list of all subfolders of the given folder.

`makefolder` (name)
  Create a new folder.

`deletefolder` (name)
  Delete a folder - must have no subfolders.

`openfolder` (name)
  Return a new open folder object.