rxjs - 用 ConcatMap 替换 SetTimeout

Question

我想用 Concat MAp 替换 setTimeout，这个例子我该怎么做？

initiate(){
    this.getInstrumentsDetails(this.svm);
    // this.getGraphicWindow();
    setTimeout(() => {
        this.getH(this.svm);
    }, 800);
    setTimeout(() => {
        this.getGraphicWindow();
    }, 1000);
    setTimeout(() => {
        this.transactionMode = this.shrd.getData('transactionMode');
    }, 1200);
}