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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 _decompress(self, fp):
 """ Internal function for decompressing a backup file with the DEFLATE algorithm :rtype: Proxy """

        decompressor = zlib.decompressobj()
        if self.stream:
            return Proxy(decompressor.decompress, fp)
        else:
            out = io.BytesIO(decompressor.decompress(fp.read()))
            out.write(decompressor.flush())
            out.seek(0)
            return out