text: 
  import { bindCallback } from "rxjs";
  
  // "bindCallback" Give it a function “f” of type f(x, callback) and it
  // will return a function "g” that when called as g(x) will output an
  // Observable.
  
  const aCallbackFunction = (a, b, callback = (value) => value) => {
    if (a < 0) throw Error('"a" < 0');
  
    setTimeout(() => {
      callback(a + b);
    }, 1000);
  };
  
  const bound = bindCallback(aCallbackFunction);
  
  const result$ = bound(300, 200);
  
  console.log('--- observablue bindCallBack ---');
  result$.subscribe({
    next: (value) => console.log('Result:', value),
    error: (error) => console.log('ERROR:', error),
    complete: () => console.log('--- complete ---')
  });
  