text: /**
   * @license
   * Copyright 2019 Google LLC
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /**
   * @fileoverview Generator for unique element IDs.
   * For UUIDs use Blockly.utils.genUid. The ID generator should primarily be
   * used for IDs that end up in the DOM.
   * @author samelh@google.com (Sam El-Husseini)
   */
  'use strict';
  
  goog.provide('Blockly.utils.IdGenerator');
  
  
  /**
   * Next unique ID to use.
   * @type {number}
   * @private
   */
  Blockly.utils.IdGenerator.nextId_ = 0;
  
  /**
   * Gets the next unique ID.
   * IDs are compatible with the HTML4 id attribute restrictions:
   * Use only ASCII letters, digits, '_', '-' and '.'
   * @return {string} The next unique identifier.
   */
  Blockly.utils.IdGenerator.getNextUniqueId = function () {
      return 'blockly:' + (Blockly.utils.IdGenerator.nextId_++).toString(36);
  };
  