@Override
 public Set<ValueSpecification> getResults(
     FunctionCompilationContext context, ComputationTarget target) {
   return ImmutableSet.of(
       new ValueSpecification(
           ValueRequirementNames.TARGET, target.toSpecification(), ValueProperties.all()));
 }
 @Override
 public Set<ValueSpecification> getResults(
     final FunctionCompilationContext context, final ComputationTarget target) {
   return Collections.singleton(
       new ValueSpecification(
           ValueRequirementNames.WEIGHT, target.toSpecification(), ValueProperties.all()));
 }
 @Override
 public Set<ValueSpecification> getResults(
     final FunctionCompilationContext context, final ComputationTarget target) {
   return Sets.newHashSet(
       new ValueSpecification(
           ValueRequirementNames.PNL_SERIES, target.toSpecification(), ValueProperties.all()));
 }