def METHOD_NAME(self):
    s = '<?xml version="1.0" encoding="UTF-8"?>\n'
    s += '<CloudFrontOriginAccessIdentityConfig xmlns="http://cloudfront.amazonaws.com/doc/2009-09-09/">\n'
    s += '  <CallerReference>%s</CallerReference>\n' % self.caller_reference
    if self.comment:
        s += '  <Comment>%s</Comment>\n' % self.comment
    s += '</CloudFrontOriginAccessIdentityConfig>\n'
    return s