Node: How to store JSON Array in google datastore -

i'm trying store following object in google datastore using nodejs returning 400 "bad request" error

{  			   "_id":{  				      "$oid":"567e9e80067de880273095e0"  				   },  				   "name":"windows 10",  				   "desc":"this test",  				   "isselfpaced":true,  				   "credit":[  				      {  				         "_id":"56640d4926b67c201b861cde",  				         "username":"akash",  				         "displayname":"gupta",  				         "email":"yesitsakash@gmail.com",  				         "role":"author"  				      }  				   ],  				    				        				   "video":{  				      "type":0,  				      "videokey":"khatemotionalfulls_lowb84c0084-836c-008c-a850-328687e23d02.mp4",  				        				   },    				   "structure":4,  				   "category":"test2",  				   "subcategory":"dfdfdf",  				   "content":[  				      {  				         "id":"a053915c-8d10-4aa8-b464-c8a99154c3af",  				         "name":"module 1",  				         "type":1,  				         "topics":[  				            "test1",  				            "test2"  				         ],  				         "children":[  				            {  				               "id":"46f18a1a-6653-41cb-be5c-002200170bb9",  				               "name":"unit 1",  				               "type":2,  				               "subtype":"1",  				               "video":{  				                  "type":0,  				                  "videokey":"vid-20150920-wa0017ee56049d-2b08-aeb5-9b9c-b5188b1f7324.mp4",  				                    				               },  				               "note":"<ul><li><b>this test<\/b><\/li><\/ul>",  				               "isselfpaced":true  				            },  				            {  				               "id":"da4f53a3-7ea2-4fa8-9d48-4d7199a3450c",  				               "name":"quiz 1",  				               "type":2,  				               "subtype":3,  				               "questions":[  				                  {  				                     "question":"new question",  				                     "options":[  				                        {  				                           "text":"option 1",  				                           "correct":true  				                        }  				                     ]  				                  }  				               ],  				               "isselfpaced":true  				            }  				         ],  				         "time":3,  				         "isselfpaced":true,  				         "desc":"this test"  				      }  				   ],  				   "createdby":{  				      "displayname":"gupta",  				      "id":"56640d4926b67c201b861cde"  				   },  				   "createdat":{  				      "$date":"2016-01-10t17:51:15.635z"  				   },  				   "startdate":"1970-01-01t00:00:00.000z",  				   "enddate":"1970-01-01t00:00:00.000z",  				   "ispublish":true  				};  	  datastore.insert('test2','test2',data,function(err,key){  		  if(err){  			  res.status(500).end();  		  }  		  else{  			  res.send(key);  		  }  	  });  	});

nodejs code:

var keyobject = dataset.key({  		  namespace: namespace,  		  path: [collectionname,utility.getguid()]  		});  	dataset.save({key:keyobject,data:data,method:'insert'},function(err) {  		if(err){  			callback(err,null);  		}  		else{  			callback(null,keyobject.path[1]);  		}  		  	});

simpler scenario wirking how can store json array in google datastore using nodejs

the issue json payload malformed.