code: func (s *ProjectsService) DeleteBranch(projectName, branchID string) (*Response, error) {
  	u := fmt.Sprintf("projects/%s/branches/%s", url.QueryEscape(projectName), url.QueryEscape(branchID))
  	return s.client.DeleteRequest(u, nil)
  }
docs: // DeleteBranch deletes a branch.
  //
  // Gerrit API docs: https://gerrit-review.googlesource.com/Documentation/rest-api-projects.html#delete-branch