def train(self, recall=0.95, index_predicates=True):  # pragma: no cover
        """
        Keyword arguments:

        maximum_comparisons -- The maximum number of comparisons a
                               blocking rule is allowed to make.

                               Defaults to 1000000

        recall -- The proportion of true dupe pairs in our training
                  data that that we the learned blocks must cover. If
                  we lower the recall, there will be pairs of true
                  dupes that we will never directly compare.

                  recall should be a float between 0.0 and 1.0, the default
                  is 0.95

        index_predicates -- Should dedupe consider predicates that
                            rely upon indexing the data. Index predicates can
                            be slower and take susbstantial memory.

                            Defaults to True.
        """
        examples, y = flatten_training(self.training_pairs)
        self.classifier.fit(self.data_model.distances(examples), y)

        self.predicates = self.active_learner.learn_predicates(
            recall, index_predicates)
        self.blocker = blocking.Blocker(self.predicates)
        self.blocker.resetIndices()
Keyword arguments:

        maximum_comparisons -- The maximum number of comparisons a
                               blocking rule is allowed to make.

                               Defaults to 1000000

        recall -- The proportion of true dupe pairs in our training
                  data that that we the learned blocks must cover. If
                  we lower the recall, there will be pairs of true
                  dupes that we will never directly compare.

                  recall should be a float between 0.0 and 1.0, the default
                  is 0.95

        index_predicates -- Should dedupe consider predicates that
                            rely upon indexing the data. Index predicates can
                            be slower and take susbstantial memory.

                            Defaults to True.