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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_stream(self, rel_path, cb=None, return_meta=False):
 """Return the object as a stream"""

        from boto.s3.key import Key
        from boto.exception import S3ResponseError

        import StringIO
        from . import MetadataFlo

        b = StringIO.StringIO()
        try:
            k = self._get_boto_key(rel_path)
            if not k:
                return None

            k.get_contents_to_file(b, cb=cb, num_cb=100)

            b.seek(0)

            if return_meta:
                d = k.metadata
                d['size'] = k.size
                d['etag'] = k.etag
            else:
                d = {}

            return MetadataFlo(b, d)

        except S3ResponseError as e:
            if e.status == 404:
                return None
            else:
                raise e