class Rufus::Scheduler

def push_pending_job (job)
    old = @pending_jobs.find { |j| j.job_id == job.job_id }
    @pending_jobs.delete(old) if old
        #
        # override previous job with same id
    if @pending_jobs.length < 1 or job.at >= @pending_jobs.last.at
        @pending_jobs << job
        return
    end
    for i in 0...@pending_jobs.length
        if job.at <= @pending_jobs[i].at
            @pending_jobs[i, 0] = job
            return # right place found
        end
    end
end