code: def _mediation_analysis(self, x=None, m=None, y=None, covar=None,
                          alpha=0.05, n_boot=500, seed=None, return_dist=False):
      
      stats = mediation_analysis(data=self, x=x, m=m, y=y, covar=covar,
                                 alpha=alpha, n_boot=n_boot, seed=seed,
                                 return_dist=return_dist)
      return stats
docs: Mediation analysis.