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_make_dir_tree.m
    path of file: ./repos/bspm/thirdparty/spm12/external/mne
    
    the code of the file until where you have to start completion: function [tree, last] = fiff_make_dir_tree(fid,dir,start,indent)
%
% [tree, last] = fiff_make_dir_tree(fid,dir,start,indent)
%
% Create the directory tree structure
%

%
%   Author : Matti Hamalainen, MGH Martinos Center

    
function [tree, last] = fiff_make_dir_tree(fid,dir,start,indent)
%
% [tree, last] = fiff_make_dir_tree(fid,dir,start,indent)
%
% Create the directory tree structure
%

%
%   Author : Matti Hamalainen, MGH Martinos Center
%   License : BSD 3-clause
%
%   Revision 1.6  2009/04/01 21:25:50  msh
%   Fixed problems with fiff nodes with no tags in them
%
%   Revision 1.5  2006/04/26 19:50:58  msh
%   Added fiff_read_mri
%
%   Revision 1.4  2006/04/23 15:29:40  msh
%   Added MGH to the copyright
%
%   Revision 1.3  2006/04/18 20:44:46  msh
%   Added reading of forward solution.
%   Use length instead of size when appropriate
%
%   Revision 1.2  2006/04/12 10:29:02  msh
%   Made evoked data writing compatible with the structures returned in reading.
%
%   Revision 1.1  2006/04/10 23:26:54  msh
%   Added fiff reading routines
%

%
%  Define the relevant constants here
%  no need to get the whole fiff_define_costants
%
FIFF_BLOCK_START     = 104;
FIFF_BLOCK_END       = 105;
FIFF_FILE_ID         = 100;
FIFF_BLOCK_ID        = 103;
FIFF_PARENT_BLOCK_ID = 110;

me='MNE:fiff_make_dir_tree';

verbose=0;

if nargin == 2
    indent = 0;
    start = 1;
elseif nargin == 3
    indent = 0;
elseif nargin ~= 4
    error(me,'Incorrect number of arguments');
end