Attachments do not returned after create/update of Thread in Conversation

[sphinks]

There is a problem on backend side that it does not return attachments as part of conversation entity. Typical flow:

1. Create attachment

Attachment attachment = new Attachment();
attachment.setData("Test data");
attachment.setFileName("http://developer.helpscout.net/img/logo.png");  
attachment.setMimeType("image/jpeg");  
client.createAttachment(attachment);

Raw json for this:

{
"mimeType":"image/jpeg",
"fileName":"http://developer.helpscout.net/img/logo.png",
"size":0,
"width":0,
"height":0,
"data":"Test data"
}

Response: Code 201 + HashCode = 7dd595c509909af1d2bf1f308dc628b7ba91e366
2. Add new attachment to conversation:

List<Attachment> attachments = new ArrayList<Attachment>();
attachments.add(attachment);
thread.setAttachments(attachments);

List<LineItem> threads = new ArrayList<LineItem>();
threads.add((LineItem)thread);
readConversation.setThreads(threads);
client.updateConversation(readConversation);

Raw Json:

{"id":185888453,"type":"Email","folderId":806466,"isDraft":false,"number":43,
"source":{"type":"api","via":"user"},
"owner":{"id":110114,"firstName":"Ivan","lastName":"Z","email":"sphinks@newmail.ru","type":"User"},
"mailbox":{"id":67978,"name":"Sphinks"},
"customer":{"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"Customer"},
"threadCount":2,"status":"active","subject":"It is updated!","preview":"New Text",
"createdAt":"2016-03-28T03:12:13Z",
"modifiedAt":"2016-03-28T03:12:14Z",
"createdBy":{"id":110114,"firstName":"Ivan","lastName":"Z","email":"sphinks@newmail.ru","type":"User"},
"threads":[
{"id":484195988,"type":"Customer","state":"published","body":"New Text","toList":[],"ccList":[],"bccList":[],
"attachments":[
{"mimeType":"image/jpeg",
"fileName":"http://developer.helpscout.net/img/logo.png",
"size":0,
"width":0,
"height":0,
"hash":"7dd595c509909af1d2bf1f308dc628b7ba91e366",
"data":"Test data"}
],
"status":"active",
"createdBy":   {"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"Customer"},
"createdAt":"2016-03-28T03:12:14Z"}
]
}

Response: 200.

1. Read conversation entity from server:

   readConversation = client.getConversation(testConversation.getId());

Raw Json:

{"item":
{"id":185888453,"type":"email","folderId":806466,"isDraft":false,"number":43,
"owner":{"id":110114,"firstName":"Ivan","lastName":"Z","email":"sphinks@newmail.ru","phone":null,"type":"user"},
"mailbox":{"id":67978,"name":"Sphinks"},
"customer":{"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"customer","emails":["help@helpscout.net","customer@example.com"]},
"threadCount":2,"status":"active",
"subject":"It is updated!",
"preview":"New Text",
"createdBy":{"id":110114,"firstName":"Ivan","lastName":"Z","email":"sphinks@newmail.ru","phone":null,"type":"user"},
"createdAt":"2016-03-28T00:12:13Z",
"modifiedAt":"2016-03-28T00:12:14Z",
"closedAt":null,
"closedBy":null,
"source":{"type":"api","via":"user"},
"cc":[],"bcc":[],
"tags":null,
"threads":[
{"id":484195988,"type":"customer","assignedTo":null,"status":"active","createdAt":"2016-03-28T00:12:14Z","openedAt":null,
"createdBy":{"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"customer","emails":["help@helpscout.net","customer@example.com"]},
"source":{"type":"api","via":"customer"},
"actionType":null,"actionSourceId":null,"fromMailbox":null,"state":"published",
"customer":{"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"customer","emails":["help@helpscout.net","customer@example.com"]},
"body":"New Text","to":null,"cc":[],"bcc":[],
"attachments":null,
"savedReplyId":null,
"createdByCustomer":true},
{"id":484195986,"type":"customer",
"assignedTo":{"id":110114,"firstName":"Ivan","lastName":"Z","email":"sphinks@newmail.ru","phone":null,"type":"user"},
"status":"active","createdAt":"2016-03-28T00:12:13Z","openedAt":null,
"createdBy":{"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"customer","emails":["help@helpscout.net","customer@example.com"]},
"source":{"type":"api","via":"customer"},"actionType":null,"actionSourceId":null,"fromMailbox":null,"state":"published",
"customer":{"id":74921843,"firstName":"Help","lastName":"Scout","email":"customer@example.com","phone":"855-435-7726","type":"customer","emails":["help@helpscout.net","customer@example.com"]},
"body":"Hello. I need some help.","to":null,"cc":[],"bcc":[],
"attachments":null,
"savedReplyId":null,
"createdByCustomer":true}]}}

As result there is no attachments. Possible two variants:

1. Attachment were created in wrong way (missed some field) - then server should not return code 201 and this should be fixed.
2. Attachment were created, but not returned as part of conversation entity.