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: pspm_load1.m
    path of file: ./repos/PsPM/src
    
    the code of the file until where you have to start completion: function varargout = pspm_load1(fn, action, savedata, options)
% ● Format
%   [sts, data, mdltype] = pspm_load1(fn, action, savedata, options)
% ● Arguments
%         fn: filename
%     action: (default 'none'):
%             'none':   check whether file is valid at all
%             'stats':  retrieve stats struct with fields .stats
%                       and .names
%             'cond':   for GLM - retrieve stats struct using only
%                       first regressor/basis function for each condition
%                       for models with 2D stats structure - retrieve
%                       mean parameter values per condition, based on
%                       unique trial names
%             'recon':  (for GLM) retrieve stats struct using
%                       reconstructed responses (which are at the same
%                       time written into the glm struct as glm.recon)
%               'con':  retrieve full con structure
%               'all':  retrieve the full first level structure
%           'savecon':  add contrasts to file, use an additional
%                       input argument data that contains the contrasts
%              'save':  check and save first levle model, use an additional

    
function varargout = pspm_load1(fn, action, savedata, options)
% ● Format
%   [sts, data, mdltype] = pspm_load1(fn, action, savedata, options)
% ● Arguments
%         fn: filename
%     action: (default 'none'):
%             'none':   check whether file is valid at all
%             'stats':  retrieve stats struct with fields .stats
%                       and .names
%             'cond':   for GLM - retrieve stats struct using only
%                       first regressor/basis function for each condition
%                       for models with 2D stats structure - retrieve
%                       mean parameter values per condition, based on
%                       unique trial names
%             'recon':  (for GLM) retrieve stats struct using
%                       reconstructed responses (which are at the same
%                       time written into the glm struct as glm.recon)
%               'con':  retrieve full con structure
%               'all':  retrieve the full first level structure
%           'savecon':  add contrasts to file, use an additional
%                       input argument data that contains the contrasts
%              'save':  check and save first levle model, use an additional
%                       input argument data that contains the model struct
%   savedata: for 'save' option - a struct containing the model as only field
%             for 'savecon' option - contains the con structure
%    options: .zscored. zscore data - substract the mean and divide
%                         by the standard deviation.
%             .overwrite for 'save'
%                        [logical] (0 or 1)
%                        Define whether to overwrite existing output files or not.
%                        Default value: determined by pspm_overwrite.
% ● Output
%       data:   depend