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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _mediation_analysis(self, x=None, m=None, y=None, covar=None, alpha=0.05, n_boot=500, seed=None, return_dist=False):
 """Mediation analysis."""

    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