//we get the property type for an associated entity
final int propertyIndex = getPropertyIndex( propertyName );
final GridType gridUniqueKeyType = getUniqueKeyTypeFromAssociatedEntity( propertyIndex, propertyName );
//get the associated property index (to get its column names)
//find the ids per unique property name
AssociationKeyMetadata associationKeyMetadata = associationKeyMetadataPerPropertyName.get( propertyName );
if ( associationKeyMetadata == null ) {
throw new AssertionFailure( "loadByUniqueKey on a non EntityType:" + propertyName );
}
AssociationPersister associationPersister = new AssociationPersister(
getMappedClass()