Cloud Firestore REST API。如何在一个请求中创建多个文档？

POST https://firestore.googleapis.com/v1/projects/{project_id}/databases/{database_id}/documents:commit

{
  "writes": [
    {
      "insert": {
        "document": {
          "name": "projects/{project_id}/databases/{database_id}/documents/{collection_id}/{document_id1}",
          "fields": {
            "field1": {
              "stringValue": "value1"
            },
            "field2": {
              "stringValue": "value2"
            }
          }
        }
      }
    },
    {
      "insert": {
        "document": {
          "name": "projects/{project_id}/databases/{database_id}/documents/{collection_id}/{document_id2}",
          "fields": {
            "field1": {
              "stringValue": "value3"
            },
            "field2": {
              "stringValue": "value4"
            }
          }
        }
      }
    }
  ]
}