Leonardo keyboard on MAC book

Projects General Guidance
1

Hi all,
I'm trying to build a keyboard with only modifier keys (SHIFT, Control, Option, Command) using Leonardo for my macbook.
My ultimate aim is, if I want to type 'A', I can be able to press and hold SHIFT key on Leonardo keyboard and press 'a' on my macbook's keyboard.

But the problem I'm facing now is I couldn't able to send press and hold key command using following line.

Keyboard.press(KEY_RIGHT_SHIFT);

Is there any way to send keydown and keyup commands separately from Leonardo keyboard to macbook?
Otherwise how can I emulate key hold event in macOS (Sierra Version 10.12.X)?

2

This may help.

3

Thank you Riva,
It is not helping me. Actually, it works fine when I send both key combination (shift + 'a') from Leonardo keyboard.

But on my case, I would like to emulate shift key press and hold from Leonardo keyboard. At the same time I'll send 'a' character from macbook's native keyboard. At the end I'm expecting the same result as (shift + 'a')