code: @Nonnull
    public TriggerBuilder <T> forJob (@Nonnull final IJobDetail jobDetail)
    {
      final JobKey k = jobDetail.getKey ();
      if (k.getName () == null)
        throw new IllegalArgumentException ("The given job has not yet had a name assigned to it.");
      m_aJobKey = k;
      return this;
    }
docs: Set the identity of the Job which should be fired by the produced Trigger,
  by extracting the JobKey from the given job.
  
  @param jobDetail
  the Job to fire.
  @return the updated TriggerBuilder
  @see ITrigger#getJobKey()