如何使用rxjs提早摆脱捕获链？

import { throwError, of } from 'rxjs';
import { catchError } from 'rxjs/operators';

const source$ = throwError('Error')
  .pipe(
    catchError(error => {
      // 处理错误
      return of('Fallback Value');
    })
  )
  .subscribe(value => {
    console.log(value);
  });

import { throwError, of } from 'rxjs';
import { mergeMap } from 'rxjs/operators';

const source$ = of('Value')
  .pipe(
    mergeMap(value => {
      // 处理异步操作
      return throwError('Error');
    }),
    catchError(error => {
      // 处理错误
      return of('Fallback Value');
    })
  )
  .subscribe(value => {
    console.log(value);
  });

import { throwError, of } from 'rxjs';

const source$ = of('Value')
  .pipe(
    mergeMap(value => {
      // 处理异步操作
      if (value === 'Error') {
        return throwError('Error');
      }
      return of(value);
    })
  )
  .subscribe(
    value => {
      console.log(value);
    },
    error => {
      // 处理错误
      console.log('Fallback Value');
    }
  );