UITouch event backtrace

touchevent.txt

(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
  * frame #0: 0x0000000102d99ca0 touchDemo`-[ViewController touchesBegan:withEvent:](self=0x000000013f0097a0, _cmd="touchesBegan:withEvent:", touches=1 element, event=0x00000002837fc300) at ViewController.m:23:20
    frame #1: 0x0000000190346c30 UIKitCore`forwardTouchMethod + 344
    frame #2: 0x0000000190346ac0 UIKitCore`-[UIResponder touchesBegan:withEvent:] + 64
    frame #3: 0x0000000190355448 UIKitCore`-[UIWindow _sendTouchesForEvent:] + 496
    frame #4: 0x0000000190356f9c UIKitCore`-[UIWindow sendEvent:] + 3976
    frame #5: 0x0000000190330bc0 UIKitCore`-[UIApplication sendEvent:] + 712
    frame #6: 0x00000001903b8118 UIKitCore`__dispatchPreprocessedEventFromEventQueue + 7360
    frame #7: 0x00000001903bb070 UIKitCore`__processEventQueue + 6460
    frame #8: 0x00000001903b25f4 UIKitCore`__eventFetcherSourceCallback + 160
    frame #9: 0x000000018d96b81c CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
    frame #10: 0x000000018d96b718 CoreFoundation`__CFRunLoopDoSource0 + 208
    frame #11: 0x000000018d96aa28 CoreFoundation`__CFRunLoopDoSources0 + 268
    frame #12: 0x000000018d964d20 CoreFoundation`__CFRunLoopRun + 824
    frame #13: 0x000000018d9644bc CoreFoundation`CFRunLoopRunSpecific + 600
    frame #14: 0x00000001a4476820 GraphicsServices`GSEventRunModal + 164
    frame #15: 0x0000000190311164 UIKitCore`-[UIApplication _run] + 1072
    frame #16: 0x0000000190316840 UIKitCore`UIApplicationMain + 168
    frame #17: 0x0000000102d9a10c touchDemo`main(argc=1, argv=0x000000016d06b858) at main.m:17:12
    frame #18: 0x000000018d62be40 libdyld.dylib`start + 4