Ensures dependencey or indepdendency between rows with respect to
        columns.

def ensure_row_dep_constraint(
            self, M_c, T, X_L, X_D, row1, row2, dependent=True, wrt=None,
            max_iter=100, force=False):
        """Ensures dependencey or indepdendency between rows with respect to
        columns."""
        X_L_list, X_D_list, was_multistate = su.ensure_multistate(X_L, X_D)

        if force:
            raise NotImplementedError
        else:
            kernel_list = ('row_partition_assignements',)
            for i, (X_L_i, X_D_i) in enumerate(zip(X_L_list, X_D_list)):

                iters = 0
                X_L_tmp = copy.deepcopy(X_L_i)
                X_D_tmp = copy.deepcopy(X_D_i)

                while not self.assert_row(
                        X_L_tmp, X_D_tmp, row1, row2,
                        dependent=dependent, wrt=wrt):
                    if iters >= max_iter:
                        raise RuntimeError(
                            'Maximum ensure iterations reached.')
                    # XXX No seed?
                    res = self.analyze(
                        M_c, T, X_L_i, X_D_i, kernel_list=kernel_list,
                        n_steps=1, r=(row1,))
                    X_L_tmp = res[0]
                    X_D_tmp = res[1]
                    iters += 1

                X_L_list[i] = X_L_tmp
                X_D_list[i] = X_D_tmp

        if was_multistate:
            return X_L_list, X_D_list
        else:
            return X_L_list[0], X_D_list[0]