@SuppressWarnings("unchecked")
  public Class<? extends Reducer<?,?,?,?>> getCombinerClass() 
     throws ClassNotFoundException {
    return (Class<? extends Reducer<?,?,?,?>>) 
      conf.getClass(COMBINE_CLASS_ATTR, null);
  }
@ SuppressWarnings ( "unchecked" ) public Class < ? extends Reducer < ? , ? , ? , ? > > getCombinerClass ( ) throws ClassNotFoundException { return ( Class < ? extends Reducer < ? , ? , ? , ? > > ) conf . getClass ( COMBINE_CLASS_ATTR , null ) ; }
Get the combiner class for the job.

@return the combiner class for the job.