question: public static Tuple min ( Iterator tuples , String field , Comparator cmp ) { Tuple t = null , tmp ; Object min = null ; if ( tuples . hasNext ( ) ) { t = ( Tuple ) tuples . next ( ) ; min = t . get ( field ) ; } while ( tuples . hasNext ( ) ) { tmp = ( Tuple ) tuples . next ( ) ; Object obj = tmp . get ( field ) ; if ( cmp . compare ( obj , min ) < 0 ) { t = tmp ; min = obj ; } } return t ; }
target:  Get the Tuple with the minimum data field value.