Reported by joe.niemiec@mongodb.com 

AtlasStreamProcessing> sp.process([{$source: {connectionName: "Cluster2_ReadWrite", db: "test10", coll: "test"}}, {$replaceRoot: {newRoot: "$fullDocument"}}])

{

  _id: ObjectId("665f278b447edf522dc10ac2"),

  a: 1,

  _stream_meta: {

    source:

{       type: 'atlas'     }

  }

}

{

  _id: ObjectId("665f2791447edf522dc10ac3"),

  a: 1,

  _stream_meta: {

    source:

{       type: 'atlas'     }

  }

}