vendor/yiisoft/multiparser/ParserConfigurator.php

<?php
namespace yii\multiparser;
class ParserConfigurator
{
    protected static $configuration = [
        'csv' =>
            ['web' =>
                ['class' => 'backend\components\parsers\CustomCsvParser',
                    'auto_detect_first_line' => true,]]];
    public static function getConfiguration($extension, $mode)
    {
        if (!isset( self::$configuration[$extension] )){
            throw new \ErrorException( "Parser do not maintain file with extension  {$extension}");
        }
        if (!isset( self::$configuration[$extension][$mode] )){
            throw new \ErrorException( "Parser configurator do not have settings for {$mode} mode");
        }
        return self::$configuration[$extension][$mode];
    }
}