@Override
 public DistinctMarketDataSelector findMatchingSelector(
     StructureIdentifier<?> structureId,
     String calculationConfigurationName,
     SelectorResolver resolver) {
   return _structureId.equals(structureId) ? this : null;
 }
 @Override
 public boolean equals(Object o) {
   if (this == o) {
     return true;
   }
   if (o == null || getClass() != o.getClass()) {
     return false;
   }
   return _structureId.equals(((ExactMatchMarketDataSelector) o)._structureId);
 }
 @Override
 public int hashCode() {
   return _structureId.hashCode();
 }