@staticmethod
    def _contingency(n_ii, n_ix_xi_tuple, n_xx):
        """Calculates values of a bigram contingency table from marginal values."""
        (n_ix, n_xi) = n_ix_xi_tuple
        n_oi = n_xi - n_ii
        n_io = n_ix - n_ii
        return (n_ii, n_oi, n_io, n_xx - n_ii - n_oi - n_io)
dataset/ETHPy150Open nltk/nltk/nltk/metrics/association.py/BigramAssocMeasures._contingency/original