Sample a sequence of items from the pool

        Parameters
        ----------
        n_to_sample : int
            number of items to sample

def sample(self, n_to_sample, **kwargs):
        """Sample a sequence of items from the pool

        Parameters
        ----------
        n_to_sample : int
            number of items to sample
        """
        n_to_sample = verify_positive(int(n_to_sample))

        n_remaining = self._max_iter - self.t_

        if n_remaining == 0:
            if (not self.replace) and (self._n_items == self._max_iter):
                raise Exception("All items have already been sampled")
            else:
                raise Exception("No more space available to continue sampling. "
                                "Consider re-initialising with a larger value "
                                "of max_iter.")

        if n_to_sample > n_remaining:
            warnings.warn("Space only remains for {} more iteration(s). "
                          "Setting n_to_sample = {}.".format(n_remaining, \
                          n_remaining))
            n_to_sample = n_remaining

        for _ in range(n_to_sample):
            self._iterate(**kwargs)