title: what is the difference between setting minimum interval and settting fetch withExpirationDuration in Firebase remote config?
body: <p>from the documentation in <a href="https://firebase.google.com/docs/remote-config/use-config-ios" rel="nofollow noreferrer">here</a> it is said that I have to set the setting for remote config like this</p>
  
  <pre><code>let settings = RemoteConfigSettings()
  settings.minimumFetchInterval = 0
  remoteConfig.configSettings = settings
  </code></pre>
  
  <p>I assume the code above is used to always fetch the data from remote (to avoid 12 hours waiting, for testing). but I also find the code below to fetch the value using expiration duration</p>
  
  <pre><code>    let fetchDuration: TimeInterval = 0
  
      remoteConfig.fetch(withExpirationDuration: fetchDuration) { (status, error) in
  
          if let error = error {
              // show the error
          } else {
              // do something
          }
  
      }
  </code></pre>
  
  <p>what is the difference between these two ? which one is used for testing to avoid waiting 12 hours ?</p>