static typeFromString_(name) {
    goog.asserts.assert(
        name.length == 4,
        'Mp4 box names must be 4 characters long');

    let code = 0;
    for (const chr of name) {
      code = (code << 8) | chr.charCodeAt(0);
    }
    return code;
  }
Convert an ascii string name to the integer type for a box.

@param {string} name The name of the box. The name must be four
                     characters long.
@return {number}
@private