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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 _CompressHistogram(self, histo_ev):
 """Callback for _ProcessHistogram."""

    return CompressedHistogramEvent(
        histo_ev.wall_time,
        histo_ev.step,
        compressor.compress_histogram_proto(
            histo_ev.histogram_value, self._compression_bps))