Return a list of ``(text, replaced_count, mask)``
        tuples with n_samples versions of text with some words replaced.
        By default words are replaced with '', i.e. removed.

def replace_random_tokens(self,
                              n_samples,  # type: int
                              replacement='',  # type: str
                              random_state=None,
                              min_replace=1,  # type: Union[int, float]
                              max_replace=1.0,  # type: Union[int, float]
                              group_size=1  # type: int
                              ):
        # type: (...) -> List[Tuple[str, int, np.ndarray]]
        """ 
        Return a list of ``(text, replaced_count, mask)``
        tuples with n_samples versions of text with some words replaced.
        By default words are replaced with '', i.e. removed.
        """
        n_tokens = len(self.tokens)
        indices = np.arange(n_tokens)
        if not n_tokens:
            nomask = np.array([], dtype=int)
            return [('', 0, nomask)] * n_samples

        min_replace, max_replace = self._get_min_max(min_replace, max_replace,
                                                     n_tokens)
        rng = check_random_state(random_state)
        replace_sizes = rng.randint(low=min_replace, high=max_replace + 1,
                                    size=n_samples)
        res = []
        for num_to_replace in replace_sizes:
            idx_to_replace = rng.choice(indices, num_to_replace, replace=False)
            idx_to_replace = np.array([idx_to_replace] + [
                idx_to_replace + shift for shift in range(1, group_size)
            ]).ravel()
            padded_size = n_tokens + group_size - 1
            mask = indices_to_bool_mask(idx_to_replace, padded_size)[:n_tokens]
            s = self.split.masked(mask, replacement)
            res.append((s.text, num_to_replace, mask))
        return res