code: function() {
        var h = this.history;
        h.commit();
  
        var start = select.cursorPos(this.container, true),
            end = select.cursorPos(this.container, false);
        if (!start || !end) return "";
  
        if (start.node == end.node)
          return h.textAfter(start.node).slice(start.offset, end.offset);
  
        var text = [h.textAfter(start.node).slice(start.offset)];
        for (var pos = h.nodeAfter(start.node); pos != end.node; pos = h.nodeAfter(pos))
          text.push(h.textAfter(pos));
        text.push(h.textAfter(end.node).slice(0, end.offset));
        return cleanText(text.join("\n"));
      }
docs: Retrieve the selected text.