code: public MergeRequest createMergeRequest(Object projectIdOrPath, String sourceBranch, String targetBranch, String title, String description, Integer assigneeId,
                  Integer targetProjectId, String[] labels, Integer milestoneId, Boolean removeSourceBranch) throws GitLabApiException {
         return createMergeRequest(projectIdOrPath, sourceBranch, targetBranch, title, description, assigneeId, targetProjectId, labels, milestoneId, removeSourceBranch, null);
      }
docs: Creates a merge request and optionally assigns a reviewer to it.
  
  <pre><code>GitLab Endpoint: POST /projects/:id/merge_requests</code></pre>
  
  @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
  @param sourceBranch the source branch, required
  @param targetBranch the target branch, required
  @param title the title for the merge request, required
  @param description the description of the merge request
  @param assigneeId the Assignee user ID, optional
  @param targetProjectId the ID of a target project, optional
  @param labels labels for MR, optional
  @param milestoneId the ID of a milestone, optional
  @param removeSourceBranch Flag indicating if a merge request should remove the source branch when merging, optional
  @return the created MergeRequest instance
  @throws GitLabApiException if any exception occurs