this function is not necessary ... you should have modified existing ```gitPull``` to accept argument ```remote``` same way ```gitPush``` does it now, so:
```
gitPull: function (remote) {
            remote = remote || "";
            return this.executeCommand(this._git + " pull " + remote + " --ff-only");
        },
```
and you can delete ```gitPullUpstream``` for now, or make it mirror ```gitPushUpstream``` with ```upstream, branch``` arguments