/**
 * MathQuill master                http://mathquill.com
 * by Han, Jeanine, and Mary  maintainers@mathquill.com
 *
 * This Source Code Form is subject to the terms of the
 * Mozilla Public License, v. 2.0. If a copy of the MPL
 * was not distributed with this file, You can obtain
 * one at http://mozilla.org/MPL/2.0/.
 */
Source Code of MathQuill: https://github.com/mathquill/mathquill/tree/v0.10.1 (Section 3.2)