问Leaflet -等同于L.GridLayer和L.VectorGrid.Slicer的eachLayer()

EN

// want to do something like this; layer groups defined previously
L.geoJSON(usData, {
  style: // styling logic
})
 .eachLayer(layer => {
   layerGroup1.addLayer(layer);
   if (category2.indexOf(layer.someProperty) !== -1) {
     layerGroup2.addLayer(layer);
   }
   if (category3.indexOf(layer.someProperty) !== -1) {
     layerGroup3.addLayer(layer);
   }
})
 .addTo(mapObject);

// no eachLayer() method for grid layers or slicers; how could you do this with grid layers?
L.vectorGrid.slicer(usData, {
  vectorTileLayerStyles: {
    sliced: properties => someFunction(properties)
  },
  interactive: true
})
 .eachLayer(layer => {
   // do something with each layer
})
 .addTo(mapObject);