How to use the libpysal.weights.attach_islands function in libpysal

if weights_kwargs:
            w0 = W.from_dataframe(df, **weights_kwargs)
        else:
            w0 = W.from_dataframe(df)
        w1 = KNN.from_dataframe(df, k=1)
        ws = [w0, w1]

        if threshold_variable and threshold_variable != "count":
            data[threshold_variable] = gdf[threshold_variable]
            threshold_var = data.threshold_variable.values
            ws[0] = attach_islands(ws[0], ws[1])

        elif threshold_variable == "count":
            threshold_var = np.ones(len(data.loc[time]))
            ws[0] = attach_islands(ws[0], ws[1])

        else:
            threshold_var = None

        model = specification[method](
            df[columns],
            w=ws[0],
            n_clusters=n_clusters,
            threshold_variable=threshold_var,
            threshold=threshold,
            **kwargs,
        )

        labels = model.labels_.astype(str)
        clusters = pd.DataFrame(
            {model_name: labels, time_var: df[time_var], id_var: df[id_var]}