fetch(url.toString(), {method: method})
      .then((response) => { done(response.ok); })
      .catch((error) => { done(false); });
}

// Initialize handlers for saving/loading configurations.
function initConfigManager() {
  'use strict';

  // Initialize various elements.
  function elem(id) {
    const result = document.getElementById(id);
    if (!result) console.warn('element ' + id + ' not found');