remove (windowId) {
    const { _windows } = this
    const window = this.get(windowId)
    if (window) {
      window.removeAllListeners('window-focus')

      this._windowActivity.delete(windowId)
      const nextWindowId = this._windowActivity.getNewest()
      this.setActiveWindow(nextWindowId)

      _windows.delete(windowId)
    }
    return window
  }
Remove the given window by id.

NOTE: All window "window-focus" events listeners are removed!

@param {string} windowId The window id.
@returns {IApplicationWindow} Returns the application window. We no longer take ownership.