code: function hyphenate(str) {
    // Catch booleans.
    if (!str) {
      return '';
    }
  
    // Turn MozBoxSizing into -moz-box-sizing.
    return str.replace(/([A-Z])/g, (str, m1) => `-${m1.toLowerCase()}`).replace(/^ms-/, '-ms-');
  }
docs: Hyphenates a javascript style string to a css one. For example:
  MozBoxSizing -> -moz-box-sizing.
  
  @param {string|false} str The string to hyphenate.
  @return {string} The hyphenated string.