docs: function fallback( fonts ) {
      return new Promise(function (resolve, reject) {
          var divs = [];
          var body = document.body;
          fonts.forEach(function (font) {
              var div = document.createElement( 'div' );
              div.className = 'tfw-font-loader';
              div.style.fontFamily = font;
              body.appendChild( div );
          });
          // Ugly trick: juste wait 1.5 second.
          window.setTimeout(function () {
              divs.forEach(function (d) {
                  body.removeChild( d );
              });
              resolve( fonts );
          }, 1500);
      });
  }