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: spm_eeg_erp_correction.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/toolbox/MEEGtools
    
    the code of the file until where you have to start completion: function D = spm_eeg_erp_correction(S)

    
function D = spm_eeg_erp_correction(S)
% Applies corrections to ERPs or single trials as in DCM-ERP
% This can be used to make a sensor level analysis or source reconstruction
% consistent with DCM.
% FORMAT D = spm_eeg_erp_correction(S)
%
% S        - optional input struct
% (optional) fields of S:
% S.D        - MEEG object or filename of M/EEG mat-file with epoched data
% S.detrend