TEST-02: time based versioning KeyValue store

versioningKeyValueStore.js

/* TEST-02
 A simple version key value store mechanism
 NOTE: here is the example about I will use this store instance.
 
  const store = new Store();
  
  store.put('scott', 1); // => 10000
  store.put('scott', 2); // => 10010
  store.put('scott', 3); // => 10020
  store.get('robert', 9999); // => null
  store.get('scott', 9999);  // => null
  store.get('scott', 10000); // => 1
  store.get('scott', 10011); // => 2
  store.get('scott', 10019); // => 2
  store.get('scott', 10020); // => 3

*/

// NOTE: you can use lodash or any other `util libray` you want
const lodash = require('lodash');

class Store {
  put(key, value) {
    // TODO: return timestamp of this value
  }
  get(key, timestamp) {
    // TODO: return the latest value "<=" the timestamp
  }
  // Feel free to extend any method your need
}