code: def unmarshall_key(self, key):
          
          key = str(key)
          if self.escapeKeys:
              key = key.decode('hex')
          if self.compressKeys:
              key = zlib.decompress(key)
          key = pickle.loads(key)
          return key
docs: Unmarshalls a Crash key read from the database.
  
          @type  key: str or buffer
          @param key: Key to convert.
  
          @rtype:  L{Crash} key.
          @return: Converted key.