code: def dropna(self, *args, **kwargs):
          
          df = super(Ensemble, self).dropna(*args, **kwargs)
          if df is not None:
              pe = ParameterEnsemble.from_dataframe(df=df,pst=self.pst)
              pe.__istransformed = self.istransformed
              return pe
docs: overload of pandas.DataFrame.dropna()
  
          Parameters
          ----------
          *args : list
              positional args to pass to pandas.DataFrame.dropna()
          **kwargs : dict
              keyword args to pass to pandas.DataFrame.dropna()
  
          Returns
          -------
          Ensemble : Ensemble