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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 GetDecompressor(cls, compression_method):
 """Retrieves the decompressor object for a specific compression method. Args: compression_method (str):
 compression method identifier. Returns: Decompressor: decompressor or None if the compression method does not exists. """

    compression_method = compression_method.lower()
    decompressor = cls._decompressors.get(compression_method, None)
    if not decompressor:
      return None

    return decompressor()