public async Task <string> CreateEventSubscription(EventSubscription subscription)
{
subscription.Id = Guid.NewGuid().ToString();
var req = new PutItemRequest()
{
TableName = $"{_tablePrefix}-{SUBCRIPTION_TABLE}",
Item = subscription.ToDynamoMap(),
ConditionExpression = "attribute_not_exists(id)"
};
var response = await _client.PutItemAsync(req);
return(subscription.Id);
}