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_dcm_fnirs_priors.m
    path of file: ./repos/spm12/toolbox/dcm_fnirs
    
    the code of the file until where you have to start completion: function [pE,pC,x] = spm_dcm_fnirs_priors(DCM)
% Returns the priors for a one-state DCM for fNIRS.
% FORMAT:[pE,pC,x] = spm_dcm_fnirs_priors(DCM)

    
function [pE,pC,x] = spm_dcm_fnirs_priors(DCM)
% Returns the priors for a one-state DCM for fNIRS.
% FORMAT:[pE,pC,x] = spm_dcm_fnirs_priors(DCM)
%
% INPUT:
%    DCM.a,DCM.b,DCM.c,DCM.c - constraints on connections (1 - present, 0 - absent)
%    DCM.n - number of sources of interest 
%    DCM.Y.nch - number of channels of interest 
%    DCM.options.two_state:  (0 or 1) one or two states per region
%    DCM.options.stochastic: (0 or 1) exogenous or end