code: function _clearGutters(that) {
          _updateCm(that);
          if (!that.cm) {
              return;
          }
          var gutters = that.cm.getOption('gutters').slice(0),
              io = gutters.indexOf(gutterName);
          if (io !== -1) {
              gutters.splice(io, 1);
              that.cm.clearGutter(gutterName);
              that.cm.setOption('gutters', gutters);
              that.cm.off('gutterClick', function (cm, n, gutterId) {
                  gutterClick(cm, n, gutterId, that);
              });
          }
      }
docs: /*
  remove all gutters from the current document