How to create pullrequest to same branch in java program[API to call]

[basuchi]

Hello,

I am struggling to create pull request from Java code. 

PullRequestCreateRequest prCreate = new PullRequestCreateRequest.Builder()
.title("Merger Request")
.repository()//from head of the method .fromRepository()
.fromBranch(null)
.toBranchId("master")
.build();

kindly suggest to me how to progress!