Combination CTRL + SHIFT + A not work

[kxiang2016]

The 2 key combination works well. e.g. ctrl+A, ctrl+C
but when press key ctrl + shift + A
It only files event: event.ctrlKey ===true + event.keyCode === shiftLeft
But what I expect is: event.ctrlKey ===true + event.shiftKey=== true + event.keyCode ==='a'

is there anything wrong? or this react-key-handler cannot support 3 key combination?
<KeyHandler
keyEventName={KEYDOWN}
keyValue={['ArrowDown', 'ArrowUp', 'ArrowLeft', 'ArrowRight', 'Control', 'Meta', 'Delete',
'Backspace', 'a', 'c', 'e', 'p', 's', 'v', 'x']}
onKeyHandle={this.keyDownEventHandler}
/>