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: xASL_wrp_FLAIR_BiasfieldCorrection.m
    path of file: ./repos/ExploreASL/Modules/SubModule_Structural
    
    the code of the file until where you have to start completion: function xASL_wrp_FLAIR_BiasfieldCorrection(x)
%xASL_wrp_FLAIR_BiasfieldCorrection Submodule of ExploreASL Structural Module, that performs a biasfield correction on T1w
% & applies it on the FLAIR
%
% FORMAT: xASL_wrp_FLAIR_BiasfieldCorrection(x)
%
% INPUT:
%   x 	    - structure containing fields with all information required to run this submodule (REQUIRED)
%   x.P     - paths with NIfTIs for which this function should be applied to (REQUIRED)
%
% OUTPUT: n/a
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% DESCRIPTION: This submodule performs a biasfield correction on T1w and applies it on FLAIR. This can be useful, when there are large lesions
% on the FLAIR that hamper capturing the biasfield nicely on the FLAIR itself. In such cases, the biasfield of the T1w might be easier to obtain
% and should be the same as the FLAIR, provided they are scanned in the same scan session (i.e.g same scanner, same coil).
% BE CAREFUL: this submodule assumes that the biasfields of the T1w and FLAIR are comparable, which is not the case when one of the two (or both) are
% already biasfield corrected.
%
% EXAMPLE: xASL_wrp_FLAIR_BiasfieldCorrection(x);
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% __________________________________
% Copyright 2015-2019 ExploreASL
%
% 2019-05-02 HJM




%% ---------------------------------------------------------------------------------------------------
%% 1) Perform biasfield correction on T1w
xASL_spm_BiasfieldCorrection(x.P.Path_T1, x.D.SPMDIR, x.settings.Quality);


%% ---------------------------------------------------------------------------------------------------
%% 2) Apply the same biasfield to the FLAIR image (NB: assumes that the FLAIR was acquired with the same scanner/coil, & hasn't been corrected
%     for its biasfield yet, also that the T1w hasn't been corrected yet

    
function xASL_wrp_FLAIR_BiasfieldCorrection(x)
%xASL_wrp_FLAIR_BiasfieldCorrection Submodule of ExploreASL Structural Module, that performs a biasfield correction on T1w
% & applies it on the FLAIR
%
% FORMAT: xASL_wrp_FLAIR_BiasfieldCorrection(x)
%
% INPUT:
%   x 	    - structure containing fields with all information required to run this submodule (REQUIRED)
%   x.P     - paths with NIfTIs for which this function should be applied to (REQUIRED)
%
% OUTPUT: n/a
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% DESCRIPTION: This submodule performs a biasfield correction on T1w and applies it on FLAIR. This can be useful, when there are large lesions
% on the FLAIR that hamper capturing the biasfield nicely on the FLAIR itself. In such cases, the biasfield of the T1w might be easier to obtain
% and should be the same as the FLAIR, provided they are scanned in the same scan session (i.e.g same scanner, same coil).
% BE CAREFUL: this submodule assumes that the biasfields of the T1w and FLAIR are comparable, which is not the case when one of the two (or both) are
% already biasfield corrected.
%
% EXAMPLE: xASL_wrp_FLAIR_BiasfieldCorrection(x);
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% __________________________________
% Copyright 2015-2019 ExploreASL
%
% 2019-05-02 HJM




%% ---------------------------------------------------------------------------------------------------
%% 1) Perform biasfield correction on T1w
xASL_spm_BiasfieldCorrection(x.P.Path_T1, x.D.SPMDIR, x.settings.Quality);


%% ---------------------------------------------------------------------------------------------------
%% 2) Apply the same biasfield to the FLAIR image (NB: assumes that the FLAIR was acquired with the same scanner/coil, & hasn't been corrected
%     for its biasfield yet, also that the T1w hasn't been corrected yet

if xASL_exist(x.P.Path_FLAIR, 'file')
    % Create biasfield image
    StructIm_BF0 = xASL_io_Nifti2Im(x.P.Path_T1);
    StructIm_BF1 = xASL_io_Nifti2Im(x.P.Path_mT1);
    BiasfieldIM  = StructIm_BF1./StructIm_BF0;

    % Extrapolating biasfield
    fprintf('%s\n','Extrapolating biasfield:   ');
    BiasfieldIM = xASL_im_ndnanfilter(BiasfieldIM, 'gauss', [8 8 8]);
    xASL_io_SaveNifti(x.P.Path_mT1, x.P.Path_BiasField_T1, BiasfieldIM, [], false);

    % First resample to FLAIR space
    xASL_spm_reslice(x.P.Path_FLAIR, x.P.Path_BiasField_T1, [], [], x.settings.Quality, x.P.Path_BiasField_FLAIR);

    % Open FLAIR & biasfield & multiply
    IM1 = xASL_io_Nifti2Im(x.P.Path_FLAIR);
    BF1 = xASL_io_Nifti2Im(x.P.Path_BiasField_FLAIR);
    IM2 = IM1.*BF1;
    xASL_io_SaveNifti(x.P.Path_FLAIR, x.P.Path_mFLAIR, IM2, 16, false);

    xASL_Move(x.P.Path_FLAIR, x.P.Path_FLAIR_ORI);
    xASL_Move(x.P.Path_mFLAIR, x.P.Path_FLAIR,1);
    xASL_delete(x.P.Path_BiasField_FLAIR);
end