问TypeError:超级表达式必须为null或函数，而不是对象。

EN

import React, { Component } from 'react';
import { Map, TileLayer, Marker, Popup } from 'react-leaflet';
import L, { map, addTo } from 'leaflet';
import RotatedMarker from 'react-leaflet-rotatedmarker'
import './App.css'

//importing marker/icon
var ego_veh_icon = L.icon({
    iconUrl: require('./design/icons/ego_veh_arrow.svg'),
    iconSize: [150, 200],
    iconAnchor: [82.5, 40],
    popupAnchor: [0, -25],
});

var av_veh_icon = L.icon({
    iconUrl: require('./design/icons/autonom_veh_arrow.svg'),
    iconSize: [150, 200],
    iconAnchor: [82.5,55],
    popupAnchor: [-5, -25],
});

var nav_veh_icon = L.icon({
    iconUrl: require('./design/icons/non_autonom_veh_arrow.svg'),
    iconSize: [150, 200],
    iconAnchor: [82.5, 60],
    popupAnchor: [-10, -25],
});

class Map_hmi extends Component {
    constructor() {
        super();
        this.state = {
            markers: [[x, y]],
            param: null,
        };
    }

    // ego veh position 
    ego_veh = {
        lat: x,
        lng: y,
    }

     // nav veh position 
     nav_veh = {
        lat: x,
        lng: y,
    }

     // av veh1 position 
     av_veh1 = {
        lat: x,
        lng: y,
    }

    // av veh2 position 
    av_veh2 = {
        lat: x
        lng: y,
    }

    render() {
        
        const ego_veh_pos = [this.ego_veh.lat, this.ego_veh.lng]
        const nav_veh_pos = [this.nav_veh.lat, this.nav_veh.lng]
        const av_veh1_pos = [this.av_veh1.lat, this.av_veh1.lng]
        const av_veh2_pos = [this.av_veh2.lat, this.av_veh2.lng]
        return (
            // declaring the map
            <Map
                className="map"
                center={ego_veh_pos}
                zoom={15}
                zoomControl={false}
            >
                <TileLayer
                    attribution='&amp;copy <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
                    url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
                />  
                    {/* <RotatedMarker position={position} rotationAngle={180} rotationOrigin={'center'} /> */}
                    {/* ego veh */}
                    <Marker 
                        position={ego_veh_pos}
                        icon= {ego_veh_icon}>
                        <Popup>
                        EGO <br/>
                        </Popup>
                    </Marker>
                    {/* nav veh */}
                    <Marker 
                        position={nav_veh_pos}
                        icon= {nav_veh_icon}>
                        <Popup>
                        NAV <br/>
                        </Popup>
                    </Marker>
                    {/* av veh1 */}
                    <Marker 
                        position={av_veh1_pos}
                        icon= {av_veh_icon}>
                        <Popup>
                        AV <br/>
                        </Popup>
                    </Marker>
                     {/* av veh2 */}
                     <Marker 
                        position={av_veh2_pos}
                        icon= {av_veh_icon}>
                        <Popup>
                        AV <br/>
                        </Popup>
                    </Marker>
                )}
            </Map>
            
        );
    }
}

export default Map_hmi;