You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: fiff_list_dir_tree.m
    path of file: ./repos/spm12/external/mne
    
    the code of the file until where you have to start completion: function fiff_list_dir_tree(out, tree, indent)

%
% fiff_list_dir_tree(fid, tree)

    
function fiff_list_dir_tree(out, tree, indent)

%
% fiff_list_dir_tree(fid, tree)
%
% List the fiff directory tree structure
%

%
%   Author : Matti Hamalainen, MGH Martinos Center
%   License : BSD 3-clause
%
%   Revision 1.3  2009/04/01 21:25:50  msh
%   Fixed problems with fiff nodes with no tags in them
%
%   Revision 1.2  2006/04/23 15:29:40  msh
%   Added MGH to the copyright
%
%   Revision 1.1  2006/04/10 23:26:54  msh
%   Added fiff reading routines
%

global FIFF;
if isempty(FIFF)
    FIFF = fiff_define_constants();
end