public RelationMetadata GetRelationMetaData(string logicalName, string schemaName)
        {
            var key = $"MetaDataHelper.GetRelationMetaData|{logicalName}|{schemaName}";
            var cachedEntityMetaData = GetFromMemCache <RelationMetadata>(key);

            if (cachedEntityMetaData != null)
            {
                return(cachedEntityMetaData);
            }

            var retrievedMetaData = MetadataHelpers.GetRelation(service, logicalName, schemaName, CrmService.OrgId);

            if (retrievedMetaData == null)
            {
                throw new Exception($"Couldn't find metadata for relation '{schemaName}' in entity '{logicalName}'.");
            }

            return(AddToMemCache(key, retrievedMetaData));
        }