code: protected Job postJobWithDescription(JSONObject jobDescription, long notBeforeRealtimeElapsed) {
          String jobId = UUID.randomUUID().toString();
          InternalJob job = new InternalJob(jobId, jobDescription, notBeforeRealtimeElapsed);
          return post(job);
      }
docs: Creates and stores a job in the queue based on the provided description
  
  @return The stored job or null if something went wrong (the queue is full for instance)