select _ Lazy loading

<el-cascader style="width: 80%" :props="props"></el-cascader>

                props: {
    
                    lazy: true,
                    lazyLoad(node, resolve) {
    
                        console.log(node.level);
                        if (node.level == 0) {
    
                            const nodes = [{
    level: 1, value: 1, label: ' In grade one ', leaf: false}, {
    
                                level: 1,
                                value: 2,
                                label: ' second grade ',
                                leaf: false
                            }]
                            resolve(nodes);
                        } else if (node.level == 1) {
    

                            if (node.value == 1) {
    
                                const nodes = [{
    level: 1, value: 3, label: ' Class one ', leaf: true}, {
    
                                    level: 1,
                                    value: 4,
                                    label: ' Class two ',
                                    leaf: true
                                }]
                                resolve(nodes);
                            } else {
    
                                const nodes = [{
    level: 1, value: 5, label: ' Class two ', leaf: true}, {
    
                                    level: 1,
                                    value: 6,
                                    label: ' Class three ',
                                    leaf: true
                                }]
                                resolve(nodes);
                            }
                        }
                    }
                },