问我需要一个像withLatestFrom这样的运算符，除非它在两个可观察对象都发出一个值时立即触发

EN

combineLatest(
  source,
  other1.pipe(
    take(1), // only take one emission, the take(1) might kill this observable and stop further emissions but give it a try
  )
).pipe(
  withLatestFrom(other1),
).subscribe(result => {
  console.log(result);
  const source = result[0][0]; // I am not sure how to destructure it but I suspect
  const other1 = result[1]; // result will be a 2d array in the form of
                               // [[source, firstEmissionOther1], other1]
  console.log(source); 
  console.log(other1);
})

combineLatest([master$, slave$])
  .pipe(
    startWith([null, null]),
    pairwise(),
    filter(([prev, curr]) => curr[0] !== prev[0]),
    map(([prev, curr]) => curr)
  )
  .subscribe(result => console.log(JSON.stringify(result)));

combineLatest(
  source$,
  latestFrom$
).pipe(
  distinctUntilChanged((prev, curr) => prev[0] === curr[0])
)