## Verify the `username` and data shape

We verify that we get a `username`, and extract the scopes.

And then we validate that data with the Pydantic model (catching the `ValidationError` exception), and if we get an error reading the JWT token or validating the data with Pydantic, we raise the `HTTPException` we created before.

 * corresponding entries will be dropped from the cache. If an error occurs while writing a cache
 * value, the edit will fail silently. Callers should handle other problems by catching
 * `IOException` and responding appropriately.
 *
 * @constructor Create a cache which will reside in [directory]. This cache is lazily initialized on
 *     first access and will be created if it does not exist.

  //
  // A consequence of these requirements is that the delegate futures cannot be stored in
  // final fields.
  //
  // For simplicity the rest of this description will discuss Futures.catching since it is the
  // simplest instance, though very similar descriptions apply to many other classes in this file.
  //
  // In the constructor of AbstractCatchingFuture, the delegate future is assigned to a field

Caching
=======

OkHttp implements an optional, off by default, Cache. OkHttp aims for RFC correct and
pragmatic caching behaviour, following common real-world browser like Firefox/Chrome and 
server behaviour when ambiguous.

# Basic Usage

```kotlin
  private val client: OkHttpClient = OkHttpClient.Builder()
      .cache(Cache(
          directory = File(application.cacheDir, "http_cache"),
          // $0.05 worth of phone storage in 2020

       * elements from each bin must either stay at same index, or move with a power of two offset.
       * We eliminate unnecessary node creation by catching cases where old nodes can be reused
       * because their next fields won't change. Statistically, at the default threshold, only
       * about one-sixth of them need cloning when a table doubles. The nodes they replace will be

       * elements from each bin must either stay at same index, or move with a power of two offset.
       * We eliminate unnecessary node creation by catching cases where old nodes can be reused
       * because their next fields won't change. Statistically, at the default threshold, only
       * about one-sixth of them need cloning when a table doubles. The nodes they replace will be

as she swam lazily about in the pool, `and she sits purring so
nicely by the fire, licking her paws and washing her face--and
she is such a nice soft thing to nurse--and she's such a capital
one for catching mice--oh, I beg your pardon!' cried Alice again,
for this time the Mouse was bristling all over, and she felt
certain it must be really offended.  `We won't talk about her any
more if you'd rather not.'

       * elements from each bin must either stay at same index, or move with a power of two offset.
       * We eliminate unnecessary node creation by catching cases where old nodes can be reused
       * because their next fields won't change. Statistically, at the default threshold, only about

#### Caching

Config translation typically takes the overwhelming majority of Istiod's resource usage. In particular, protobuf encoding. As a result, caching has been introduced, storing the already encoded `protobuf.Any` for a given resource.

    HISTORICAL_PERFORMANCE("Historical Performance", "Once a week: Run performance tests for multiple Gradle versions", "HistoricalPerformance"),
    EXPERIMENTAL_VFS_RETENTION("Experimental FS Watching", "On demand checks to run tests with file system watching enabled", "ExperimentalVfsRetention"),
    EXPERIMENTAL_PERFORMANCE("Experimental Performance", "Try out new performance test running", "ExperimentalPerformance");

    val id: String