private void validate(ValueRange valueRangeAnnotation) {
   if (!valueRangeAnnotation.solutionProperty().equals("")) {
     throw new IllegalArgumentException(
         "The planningEntityClass ("
             + variableDescriptor.getPlanningEntityDescriptor().getPlanningEntityClass()
             + ") has a PlanningVariable annotated property ("
             + variableDescriptor.getVariableName()
             + ") of type ("
             + valueRangeAnnotation.type()
             + ") with a non-empty solutionProperty ("
             + valueRangeAnnotation.solutionProperty()
             + ").");
   }
   if (valueRangeAnnotation.planningEntityProperty().equals("")) {
     throw new IllegalArgumentException(
         "The planningEntityClass ("
             + variableDescriptor.getPlanningEntityDescriptor().getPlanningEntityClass()
             + ") has a PlanningVariable annotated property ("
             + variableDescriptor.getVariableName()
             + ") of type ("
             + valueRangeAnnotation.type()
             + ") with an empty planningEntityProperty ("
             + valueRangeAnnotation.planningEntityProperty()
             + ").");
   }
 }