title: algorithm of findKey in lodash
body: <p>I want to find key via value from object, and I find that <strong>lodash</strong> provide us convenient api <code>findKey</code> could help me.</p>
  
  <p>but my question is, how could <code>findKey</code> work? is that different from <strong>hash</strong> common key value mapping?</p>
  
  <p>I don't know anything about that, if possible, could you provide me some example to compare?</p>
  
  <p>thanks for your time!</p>