def assign(self, context):
    timestamp = context.timestamp
    start = timestamp - self.size % (timestamp - self.offset)
    return [IntervalWindow(start, start + self.size)]
dataset/ETHPy150Open GoogleCloudPlatform/DataflowPythonSDK/google/cloud/dataflow/transforms/window.py/FixedWindows.assign/swapped operands of `%`