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.
def __init__(self, id):
        super(DynamoDBStream, self).__init__(id)
        self.table = None
class DynamoDBItem(Component):
    def __init__(self, id, table=None, keys=None):
        super(DynamoDBItem, self).__init__(id)
        self.table = table
        self.keys = keys
    def __eq__(self, other):
        if not isinstance(other, DynamoDBItem):
            return False
        return (other.table == self.table and
            other.id == self.id and
            other.keys == self.keys)
    def __hash__(self):
        return hash(self.table) + hash(self.id) + hash(self.keys)
class ElasticSearch(Component):
    def __init__(self, id):
        super(ElasticSearch, self).__init__(id)
        self.indexes = []
        self.endpoint = None
    def name(self):
        return self.id.split(':domain/')[-1]
class SqsQueue(Component):