iOS 7.3.6版本，为什么没有调用initWithAppkey初始化还是获取了IFDV?

* thread #7, queue = 'serial.umeng.sdk.queue', stop reason = breakpoint 2.1

* frame #0: 0x00000001eb734210 UIKitCore`-[UIDevice identifierForVendor]

frame #1: 0x0000000102e148e8 VCore`+[UMUtils idfv] + 136

frame #2: 0x0000000102de43f4 VCore`-[UMEnvelopeBuild init] + 96

frame #3: 0x0000000102de437c VCore`___lldb_unnamed_symbol25760$$VCore + 36

frame #4: 0x000000010a594c78 libdispatch.dylib`_dispatch_client_callout + 16

frame #5: 0x000000010a596c84 libdispatch.dylib`_dispatch_once_callout + 84

frame #6: 0x0000000102de4354 VCore`+[UMEnvelopeBuild sharedInstance] + 112

frame #7: 0x0000000102e01ff0 VCore`___lldb_unnamed_symbol25789$$VCore + 788

frame #8: 0x000000010a5936f4 libdispatch.dylib`_dispatch_call_block_and_release + 24

frame #9: 0x000000010a594c78 libdispatch.dylib`_dispatch_client_callout + 16

frame #10: 0x000000010a59cbf4 libdispatch.dylib`_dispatch_lane_serial_drain + 712

frame #11: 0x000000010a59d8b4 libdispatch.dylib`_dispatch_lane_invoke + 456

frame #12: 0x000000010a5a777c libdispatch.dylib`_dispatch_workloop_worker_thread + 1148

frame #13: 0x00000001bee9e114 libsystem_pthread.dylib`_pthread_wqthread + 304

frame #14: 0x00000001beea0cd4 libsystem_pthread.dylib`start_wqthread + 4

这是调用栈，在用户同意前没有initWithAppkey，但还是获取了IFDV？请问是什么原因呢？

- UMAPM (1.6.3)

- UMCommon (7.3.6):

- UMDevice

- UMDevice (2.2.1)

当前使用版本号