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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 _compress(self, cmd):
 """Adds the appropriate command to compress the zfs stream"""

        compressor = COMPRESSORS.get(self.compressor)
        if compressor is None:
            return cmd
        compress_cmd = compressor['compress']
        return "{} | {}".format(compress_cmd, cmd)