class Github::Issues::Labels

def add(user_name, repo_name, issue_id, *args)
  params = args.extract_options!
  params['data'] = args unless args.empty?
  _update_user_repo_params(user_name, repo_name)
  _validate_user_repo_params(user, repo) unless user? && repo?
  _validate_presence_of(issue_id)
  _normalize_params_keys(params)
  post_request("/repos/#{user}/#{repo}/issues/#{issue_id}/labels", params)
end