code: def to_tuple(self):
          
          return self._tp, self._tn, self._fp, self._fn
docs: Cast to tuple.
  
          Returns
          -------
          tuple
              The confusion table as a 4-tuple (tp, tn, fp, fn)
  
          Example
          -------
          >>> ct = ConfusionTable(120, 60, 20, 30)
          >>> ct.to_tuple()
          (120, 60, 20, 30)