.input(joinWithSolutionSet)
.name(NEXT_WORKSET_REDUCER_NAME)
.build();
if (mapBeforeSolutionDelta) {
MapOperator mapper = MapOperator.builder(new IdentityMap())
.input(joinWithSolutionSet)
.name(SOLUTION_DELTA_MAPPER_NAME)
.build();
iteration.setSolutionSetDelta(mapper);
} else {