old_contents: import './index.css';
  import numeral from 'numeral';
  const courseValue = numeral(1000).format('$0,0.00');
  console.log(`I would pay ${courseValue} for this course!`);
  
new_contents: import './index.css';
  import numeral from 'numeral';
  const courseValue = numeral(1000).format('$0,0.00');
  
  debugger;
  console.log(`I would pay ${courseValue} for this course!`);
  
subject: debug with sourcemap