create exist tables in Laravel Migration

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateExistTables extends Migration
{
    private $sqlFolder = 'database/migrations/Dump20170907';
    private function getDumpSQLs()
    {
        //
        $files = scandir($this->sqlFolder);

        return collect($files)->filter(function($filename) {
            $isSQL = strpos($filename, '.sql');

            return $isSQL;
        });
    }

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        //
        $filenames = $this->getDumpSQLs();
        collect($filenames)->each(function($filename) {
            $sql = file_get_contents($this->sqlFolder . '/' . $filename);

            DB::unprepared($sql);
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        //
        $filenames = $this->getDumpSQLs();
        collect($filenames)->each(function($filename) {
            $isSQL = strpos($filename, '.sql');

            if ($isSQL !== FALSE) {
                $names = preg_split('/[_.]+/', $filename);
                array_pop($names);
                array_shift($names);

                $tableName = implode('_', $names);
                Schema::dropIfExists($tableName);
            }
        });
    }
}