May be a duplicate of https://github.com/localstack/localstack/issues/988 but due to the age I will re raise.

I'm having issues when I throw an exception in a lambda - it isn't appearing on my dead letter queue. Is there something I am missing, I would like an sqs event exception to appear on the poison queue when an exception happens.

Below is the basic config:
 ````
    sqsclient.create_queue(QueueName = 'test-queue')
    sqsclient.create_queue(QueueName = 'test-queue-poison')

    lambda_client.create_function(
            FunctionName='MyFunction',
            Runtime='dotnetcore2.1',
            Role='role',
            Handler='Handler',
            Code=code,
	    DeadLetterConfig={'TargetArn': 'test-queue-poison-arn'})

     lambda_client.create_event_source_mapping(
		EventSourceArn='test-queue-arn',
		FunctionName='MyFunction',
		Enabled=True,
		BatchSize=100,
		StartingPosition='LATEST')
````

So when I raise a new (.net)exception within the lambda function no message is going to the dead letter queue. I can confirm that all is attached together OK as all other scenarios work, and the above code is pseudo-ish.
dict_values = type({}.values())
    if isinstance(all_objects, dict_values):
        all_objects = list(all_objects)
    
    if type(all_objects) is not list:
        all_objects = [all_objects]
    found = find_object(expected_object, all_objects)
    if not found:
        raise Exception('Expected object not found: %s in list %s' % (expected_object, all_objects))
def find_object(expected_object, object_list):
    for obj in object_list:
        if isinstance(obj, list):
            found = find_object(expected_object, obj)
            if found:
                return found
        all_ok = True
        if obj != expected_object:
            if not isinstance(expected_object, dict):
                all_ok = False
            else:
                for k, v in iteritems(expected_object):
                    if not find_recursive(k, v, obj):
                        all_ok = False
                        break
        if all_ok:
            return obj
    return None
def find_recursive(key, value, obj):