code: public void setJobClass (final Class <? extends IJob> jobClass)
    {
      if (jobClass == null)
      {
        throw new IllegalArgumentException ("Job class cannot be null.");
      }
  
      if (!IJob.class.isAssignableFrom (jobClass))
      {
        throw new IllegalArgumentException ("Job class must implement the Job interface.");
      }
  
      m_aJobClass = jobClass;
    }
docs: <p>
  Set the instance of <code>Job</code> that will be executed.
  </p>
  
  @exception IllegalArgumentException
  if jobClass is null or the class is not a <code>Job</code>.