"properties": {
"type": {"type": "string", "description": "One of keyup or keydown.", "enum": ["keyup", "keydown"]},
"requestId": {"type": "string", "description": "The ID of the request."},
+ "extensionId": {"type": "string", "optional": true, "description": "The extension ID of the sender of this keyevent."},
"key": {"type": "string", "description": "Value of the key being pressed"},
"code": {"type": "string", "description": "Value of the physical key being pressed. The value is not affected by current keyboard layout or modifier state."},
"altKey": {"type": "boolean", "optional": true, "description": "Whether or not the ALT key is pressed."},