code: def get_fast_scanner(self):
          
          v0 = self.v0
          v1 = self.v1
          QS = (self._QS[0], v0 * self._QS[1])
          return FastScanner(self._y, self.X, QS, v1)
docs: Return :class:`.FastScanner` for association scan.
  
          Returns
          -------
          fast-scanner : :class:`.FastScanner`
              Instance of a class designed to perform very fast association scan.