如何在Leaflet 1.0.3中更改LineStrings的geoJSON层的样式

var map = L.map('map').setView([51.505, -0.09], 13);

L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
    attribution: 'Map data &copy; <a href="https://www.openstreetmap.org/">OpenStreetMap</a> contributors',
    maxZoom: 18
}).addTo(map);

var geojsonLayer = L.geoJSON(geojsonData).addTo(map);

function style(feature) {
    return {
        color: 'red',
        weight: 2,
        opacity: 0.5
    };
}

geojsonLayer.setStyle(style);