【phpunit】Laravel 测试的时候，如果有多个数据库怎么办？ 有大用

'mysql' => [
    'driver'    => 'mysql',
    'host'      => env('MYSQL_HOSTNAME', 'localhost'),
    'port'      => env('MYSQL_PORT', 3306),
    'database'  => env('MYSQL_DATABASE', 'forge'),
    'username'  => env('MYSQL_USER', 'forge'),
    'password'  => env('MYSQL_PASSWORD', ''),
    'charset'   => env('MYSQL_CHARSET', 'utf8mb4'),
    'collation' => env('MYSQL_COLLATION', 'utf8mb4_unicode_ci'),
    'prefix'    => env('MYSQL_PREFIX', ''),
    'timezone'  => env('MYSQL_TIMEZONE', '+08:00'),
    'strict'    => env('MYSQL_STRICT_MODE', true),
],
'new_mysql' => [
    'driver'    => 'mysql',
    'host'      => env('NEW_NEW_MYSQL_HOSTNAME', 'localhost'),
    'port'      => env('NEW_MYSQL_PORT', 3306),
    'database'  => env('NEW_MYSQL_DATABASE', 'forge'),
    'username'  => env('NEW_MYSQL_USER', 'forge'),
    'password'  => env('NEW_MYSQL_PASSWORD', ''),
    'charset'   => env('NEW_MYSQL_CHARSET', 'utf8mb4'),
    'collation' => env('NEW_MYSQL_COLLATION', 'utf8mb4_unicode_ci'),
    'prefix'    => env('NEW_MYSQL_PREFIX', ''),
    'timezone'  => env('NEW_MYSQL_TIMEZONE', '+08:00'),
    'strict'    => env('NEW_MYSQL_STRICT_MODE', true),
]

protected $connection = 'new_mysql';

'testing' => [
    'driver' => 'sqlite',
    'database' => ':memory:',
],

<env name="DB_CONNECTION" value="testing" />

public function getConnectionName()
{
    return app()->environment('testing') ? config('database.default') : 'new_mysql';
}