question: create an aggregate based map/reduce job . concode_field_sep PlaceHolder placeHolder concode_field_sep JobControl createValueAggregatorJobs concode_elem_sep JobControl createValueAggregatorJobs concode_elem_sep void main concode_elem_sep void setAggregatorDescriptors
target: JobConf function ( String arg0 [ ] ) { return createValueAggregatorJob ( arg0 , ValueAggregator . class ) ; }