code: private ConstraintRelationshipInfo relationshipInfoFromConstraintDefinition(ConstraintDefinition constraintDefinition) {
          return new ConstraintRelationshipInfo(
                  String.format("CONSTRAINT %s", constraintDefinition.toString()),
                  constraintDefinition.getConstraintType().name(),
                  Iterables.asList(constraintDefinition.getPropertyKeys()),
                  ""
          );
      }
docs: Constraint info from ConstraintDefinition for relationships
  
  @param constraintDefinition
  @return