```javascript
/**
 * moduleB.js - Another sample module.
 */

export const add = (a, b) => {
  return a + b;
};

export default class Calculator {
  constructor(initialValue = 0) {
    this.value = initialValue;
  }

  multiply(factor) {
    this.value *= factor;
    return this.value;
  }
} 
```