// Helper function gets element of type T from parent dom element
function getElement<T>(parent: HTMLElement, selector: string): Promise<T> {
  return new Promise<T>((resolve, reject) => {
    setTimeout(
      () => {
        try {
          resolve(<T><any> parent.querySelector(selector));
        } catch (error) {
          reject(error);
        }
      },
      0
    );
  });
}