def _fix_content_length(self, request):

        if request.method == 'PUT' and not 'Content-Length' in request.headers:
            request.headers['Content-Length'] = '0'
Amazon requires to have content-length header when using the put request,
dataset/ETHPy150Open smore-inc/tinys3/tinys3/auth.py/S3Auth._fix_content_length