It is my understanding that setting an environment varialbe `TEST_AWS_ACCOUNT_ID` for localstack sets that as the AWS account for the user in localstack.

However, setting it does not actually change any ARNs. For example:

1. Start localstack using `TEST_AWS_ACCOUNT_ID="111111111111" DEBUG=1 localstack start`
2. Deploy anything with an ARN (in this example I deployed a lambda)
3. Check the ARN. Example output for lambda:
```json
$ awslocal lambda list-functions
{
    "Functions": [
        {
            "FunctionName": "localtest-local-hello",
            "FunctionArn": "arn:aws:lambda:us-east-1:000000000000:function:localtest-local-hello",
            "Runtime": "nodejs10.x",
            "Role": "test_role",
            "Handler": "handler.hello",
            "CodeSize": 3077,
            "Description": "",
            "Timeout": 6,
            "MemorySize": 1024,
            "LastModified": "2019-11-06T06:43:53.451+0000",
            "CodeSha256": "V77gR13o90ET7+XquXBBc3Rxr1qDu1bE7S+A0Wbx5ys=",
            "Version": "$LATEST",
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "RevisionId": "3d4ed679-c1a9-4b7e-ad9e-f27e8543c5e9"
        }
    ]
}
```

ARN is still 000000000000
resource_type = get_resource_type(resource)
    entry = RESOURCE_TO_FUNCTION.get(resource_type)
    if entry is None:
        LOG.warning('Unknown resource type "%s": %s' % (resource_type, resource))
    return bool(entry and entry.get(ACTION_CREATE))
def is_deployed(resource_id, resources, stack_name):
    resource = resources[resource_id]
    resource_status = resource.get('__details__') or {}
    details = retrieve_resource_details(resource_id, resource_status, resources, stack_name)
    return bool(details)
def should_be_deployed(resource_id, resources, stack_name):
    """ Return whether the given resource is all of: (1) deployable, (2) not yet deployed,
        and (3) has no unresolved dependencies. """
    resource = resources[resource_id]
    if not is_deployable_resource(resource) or is_deployed(resource_id, resources, stack_name):
        return False
    res_deps = get_resource_dependencies(resource_id, resource, resources)
    return all_dependencies_satisfied(res_deps, stack_name, resources, resource_id)
def is_updateable(resource_id, resources, stack_name):
    """ Return whether the given resource can be updated or not """
    resource = resources[resource_id]
    if not is_deployable_resource(resource) or not is_deployed(resource_id, resources, stack_name):
        return False
    resource_type = get_resource_type(resource)
    return resource_type in UPDATEABLE_RESOURCES
def all_dependencies_satisfied(resources, stack_name, all_resources, depending_resource=None):