In [this PR](https://github.com/localstack/localstack/pull/1200/files) we introduced a new way of starting S3 in a separate process.

In the meantime, the service startup has been significantly reworked, and it seems that we can integrate the S3 starter into the [`multiserver.py`](https://github.com/localstack/localstack/blob/master/localstack/utils/server/multiserver.py) based loading approach that loads multiple APIs in a single process, for performance reasons. We should look into that.
return s3_truncate_result_orig(result_keys, max_keys or 1000)
    s3_truncate_result_orig = s3_responses.S3ResponseInstance._truncate_result
    s3_responses.S3ResponseInstance._truncate_result = types.MethodType(
        s3_truncate_result, s3_responses.S3ResponseInstance)
    
    
    s3_delete_keys_response_template = """<?xml version="1.0" encoding="UTF-8"?>
    <DeleteResult xmlns="http://s3.amazonaws.com/doc/2006-03-01">
    {% for k in deleted %}
    <Deleted>
    <Key>{{k.key}}</Key>
    <VersionId>{{k.version_id}}</VersionId>
    </Deleted>
    {% endfor %}
    {% for k in delete_errors %}
    <Error>
    <Key>{{k}}</Key>
    </Error>
    {% endfor %}
    </DeleteResult>"""
    def s3_bucket_response_delete_keys(self, request, body, bucket_name):