question: sum aggregate function for integral long , i.e. 64 bit integer type . concode_field_sep PlaceHolder placeHolder concode_field_sep TypedColumn<T,Double> avg concode_elem_sep TypedColumn<T,Long> count concode_elem_sep TypedColumn<T,Double> sum
target: TypedColumn < T , Long > function ( MapFunction < T , Long > arg0 ) { return new TypedSumLong < T > ( arg0 ) . toColumnJava ( ) ; }