takeUntil() 
Function
takeUntil<T>(until$:
Observable<unknown>):MaybeCancellingPipeOperator<T,T>
Emit values until the passed Observable emits.
ts
declare const read1: Read<string>;
declare const until$: Observable<unknown>;
const read: Read<string> = read1.pipe(takeUntil<string>(until$));Observable Behavior:
Works exactly like takeUntil of RxJS.
Sync Behavior:
Has no effect on sync calls. The value is just passed through.
Source: rxjs-read/src/lib/operators/take-until.operator.ts:29
Type parameters 
| Parameter | Description | 
|---|---|
| T | type of the value | 
Parameters 
| Parameter | Type | Description | 
|---|---|---|
| until$ | Observable<unknown> | Observable to cancel emissions | 
Returns 
MaybeCancellingPipeOperator<T, T>