Update the estimate after querying the label for an item

def _update_estimate_and_sampler(self, ell, ell_hat, weight, extra_info,
                                     **kwargs):
        """Update the estimate after querying the label for an item"""
        self._TP += ell_hat * ell * weight
        self._FP += ell_hat * (1 - ell) * weight
        self._FN += (1 - ell_hat) * ell * weight
        self._TN += (1 - ell_hat) * (1 - ell) * weight

        self._estimate[self.t_] = \
                self._F_measure(self.alpha, self._TP, self._FP, self._FN)