如何在mongodb中使用yii2列出所有数据库？

I need a list of databases on the current server. I am using yii2 framework. How do I get the list of databases? yii2 v2.1 has functions to get this list of databases, but I want use yii2 v2.0.

$all = Yii::$app->mongodb->createCommand()->listDatabases();

where mongodb is configured mongo instance. Response may look like:

$all:array = 
  0: array = 
    name: string = local
    sizeOnDisk: double = 83886080
    empty: bool = FALSE
  1: array = 
    name: string = testDD
    sizeOnDisk: double = 19268632576
    empty: bool = FALSE
  2: array = 
    name: string = admin
    sizeOnDisk: double = 1
    empty: bool = TRUE