code: def _compute_acq(self, x):
          
          m, s = self.model.predict(x)
          fmin = self.model.get_fmin()
          phi, Phi, u = get_quantiles(self.jitter, fmin, m, s)
          f_acqu = s * (u * Phi + phi)
          return f_acqu
docs: Computes the Expected Improvement per unit of cost