In general, you should expect one and only one "end" callback for each request call. If the request also subscribes you to future updates, in general, do not expect any additional "end" calls.
When your client initially connects and requests (for example) account or order updates, you receive an immediate "current" or "historical" complete snapshot of the relevant data. The end of that complete download is indicated by the corresponding "end" callbacks.
From that point on, only incremental updates to the initial download are sent for values that actually change. Since these are incremental, "end" callbacks really make no sense and, consequently, are not sent.
Hope that helps,
闯ü谤驳别苍
