问在浏览器中返回“不是函数”的类型记录函数

EN

interface IMyFeature {
    setupEventHandlers: () => void;
    handleDurationSelectorChange: () => void;
    fetchReportData: (durationId: number) => void;
}

class MyFeatureCode implements IMyFeature {
    constructor() {
        this.setupEventHandlers();
        this.fetchReportData(0);
    }

    setupEventHandlers(): void {
        $('#durationSelector').change(this.handleDurationSelectorChange);
    }

    handleDurationSelectorChange(): void {
        const durationId: number = Number($(this).find('option:selected').attr("id"));
        this.fetchReportData(durationId);
    }

    fetchReportData(durationId: number): void {
        const url: string = $('#formData').data().the_url;

        $.ajax({
                type: 'GET',
                url: url,
            data: { "reportFor": durationId }
            })
            .done((data: any) => {
                if (data.success === false) {
                    // Panic?
                }
                else {
                    // do something
                }
            })
            .fail((xhr: any, status: any, error: any) => {
                // log something
            })
            .always(() => {
            });
    }
}

const myFeature: IMyFeature = new MyFeatureCode();