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: import_smi.m
    path of file: ./repos/PsPM/src/Import/smi
    
    the code of the file until where you have to start completion: function [data] = import_smi(varargin)
    % import_smi is the function for importing SMI data generated by an iView eyetracker.
    % The function changes the importing method depending on input the arguments. If an
    % event file has been generated by the eyetracker software and is
    % passed as an argument, import_SMI will also import the events and store
    % them in the ouput struct, otherwise no information about blinks and saccades are
    % generated. Gaze values during blinks/saccades are set to NaN.
    %
    % FORMAT: [data] = import_smi(sample_file)
    %         [data] = import_smi(sample_file, event_file)
    %             sample_file: path to the file which contains the recorded SMI Data File
    %                          in ASCII file format
    %             event_file:  path to the file which contains the computed events of the
    %                          recorded SMI Data 
    
function [pupil_channels, pupil_units] = get_pupil_channels(columns)
    header_names_units = {...
        {'L Dia X [px]', 'diameter pixel'},...
        {'L Dia X [mm]', 'diameter mm'},...
        {'L Dia Y [px]', 'diameter pixel'},...
        {'L Dia Y [mm]', 'diameter mm'},...
        {'L Dia [px]', 'diameter pixel'},...
        {'L Dia [mm]', 'diameter mm'},...
        {'L Area [px', 'area pixel2'},...
        {'L Area [mm', 'area mm2'},...
        {'L Mapped Diameter [mm]', 'diameter mm'},...
        {'R Dia X [px]', 'diameter pixel'},...
        {'R Dia X [mm]', 'diameter mm'},...
        {'R Dia Y [px]', 'diameter pixel'},...
        {'R Dia Y [mm]', 'diameter mm'},...
        {'R Dia [px]', 'diameter pixel'},...
        {'R Dia [mm]', 'diameter mm'},...
        {'R Area [px', 'area pixel2'},...
        {'R Area [mm', 'area mm2'},...
        {'R Mapped Diameter [mm]', 'diameter mm'}...
    };
    pupil_channels = [];
    pupil_units = {};
    for i = 1:numel(header_names_units)
        idx = find(contains(columns, header_names_units{i}{1}));
        if ~isempty(idx)
            pupil_channels(end