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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 save(self, hdf5):
 """Saves this cascade into the given HDF5 file. **Parameters:** ``hdf5`` : :py:class:`bob.io.base.HDF5File` An HDF5 file open for writing """

    # write the cascade to file
    hdf5.set("Thresholds", self.thresholds)
    for i in range(len(self.cascade)):
      hdf5.create_group("Classifier_%d" % (i+1))
      hdf5.cd("Classifier_%d" % (i+1))
      self.cascade[i].save(hdf5)
      hdf5.cd("..")
    hdf5.create_group("FeatureExtractor")
    hdf5.cd("FeatureExtractor")
    self.extractor.save(hdf5)
    hdf5.cd("..")