How to Close Mobile Keyboard?

Hey! this might be a really simple question but I have a line of code that opens the native keyboard of a mobile device.

public void OpenKeyBoard(string IFValue)
if (TouchScreenKeyboard.visible == false && !IS_KeyboadOpen)
TouchScreenKeyboard.Open( IFValue, TouchScreenKeyboardType.Default, false, false, false);
IS_KeyboadOpen = true;

But what line of code can I use to Close the keyboard?
Any help appreciated!

Possibly what you are after:

With some googling it looks like the keyboard should close when its focus isnt on it anymore, ie if you tab away from the text input it should disappear without having to code anything.