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: CBIG_RF_replication_compare.m
    path of file: ./repos/CBIG/stable_projects/registration/Wu2017_RegistrationFusion/replication
    
    the code of the file until where you have to start completion: function CBIG_RF_unit_test_compare(file1, file2)
% This function compares two nifti files and returns 1 if their .vol are completely the same
% Written by Wu Jianxiao and CBIG under MIT license: https://github.com/ThomasYeoLab/CBIG/blob/master/LICENSE.md

mri1 = MRIread(file1);
mri2 = MRIread(file2);
diff = sum(abs(mri1.vol(:) - mri2.vol(:)));

disp('%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%')

    
function CBIG_RF_unit_test_compare(file1, file2)
% This function compares two nifti files and returns 1 if their .vol are completely the same
% Written by Wu Jianxiao and CBIG under MIT license: https://github.com/ThomasYeoLab/CBIG/blob/master/LICENSE.md

mri1 = MRIread(file1);
mri2 = MRIread(file2);
diff = sum(abs(mri1.vol(:) - mri2.vol(:)));

disp('%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%')
if diff > 0
  disp('%%  The two volumes are different!  %%')
else
  disp('%%  The two volumes are identical.  %%')
end