nullable in laravel migration code example

Example 1: laravel migration make column nullable

Schema::table('users', function($table)
{
    $table->string('name', 50)->nullable()->change();
});

This is the correct syntax to revert the migration:

$table->integer('user_id')->unsigned()->nullable(false)->change();

Example 2: laravel create migration

php artisan make:migration add_votes_to_users_table --table=users

php artisan make:migration create_users_table --create=users

Example 3: laravel migration integer

$table->bigInteger('votes');