How to get source branch name of merged shelve set using TFS API in C#

See more:

API

TFS

I am able to fetch list of "Edit, Merge" type change sets on a TFS branch and now I wanted to get the source branch name from where changes have been merged. Could any on help me regarding this please. I tried using QueryMergeRelationships method, but no luck.

What I have tried:

TfsTeamProjectCollection proj_coll = new TfsTeamProjectCollection(new Uri("<tfs_url>"));
vcs = (VersionControlServer)proj_coll.GetService(typeof(VersionControlServer));

//relNotesReq.SourceLocation contains path of current request
var merges = vcs.QueryMergeRelationships(relNotesReq.SourceLocation);