UnityEngine.EventSystems.EventSystem.SetSelectedGameObject C# (CSharp) Method

        public void SetSelectedGameObject(GameObject selected)
        {
            this.SetSelectedGameObject(selected, this.baseEventDataCache);
        }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetButtonDown("Pause"))
        {
            if (GameIsPaused)
            {
                Resume();
            }
            else
            {
                Pause();
            }
        }

        if (GameIsPaused || GameOverScreen.activeSelf)
        {
            if (Input.GetKeyDown(KeyCode.Space) || Input.GetButtonDown("Fire1"))
            {
                eventSystem.currentSelectedGameObject.GetComponent <Button>().onClick.Invoke();
            }

            if (eventSystem.currentSelectedGameObject != selectedGameObject)
            {
                if (eventSystem.currentSelectedGameObject == null)
                {
                    eventSystem.SetSelectedGameObject(selectedGameObject);
                }
                else
                {
                    selectedGameObject = eventSystem.currentSelectedGameObject;
                }
            }
        }
    }