strathausen/dracula — pull request #24 by Bor1s (2014-02-25 13:53:50+00:00)
Title: validates connection present for edge

Sometimes connection is undefined at show/hide Edge functions which creates a crash for 'fg' in next code:
```javascript
AbstractEdge.prototype = {
hide: function() {
this.connection.fg.hide();
this.connection.bg && this.bg.connection.hide();
}
};
```

So I believe it is good idea to check for:
```
this.connection