assertThat(parse("http://username:@host/path"))
      .isEqualTo(parse("http://username@host/path"))
  }

  @Test
  fun passwordWithEmptyUsername() {
    // Chrome doesn't mind, but Firefox rejects URLs with empty usernames and non-empty passwords.
    assertThat(parse("http://:@host/path"))
      .isEqualTo(parse("http://host/path"))
    assertThat(parse("http://:password@@host/path").encodedPassword)

### [URLs](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-http-url/)

URLs (like `https://github.com/square/okhttp`) are fundamental to HTTP and the Internet. In addition to being a universal, decentralized naming scheme for everything on the web, they also specify how to access web resources.

URLs are abstract:

 * because unequal URLs may be equal because of how they are hosted.
 *
 * ### Equal URLs should be equal
 *
 * These two URLs are semantically identical, but `java.net.URI` disagrees:
 *
 *  * http://host:80/
 *
 *  * http://host
 *
 * Both the unnecessary port specification (`:80`) and the absent trailing slash (`/`) cause URI to

```kotlin
cache.evictAll()
```

Removing individual items can be done using the urls iterator.
This would be typical after a user initiates a force refresh by a pull to refresh type action.

```java
    val urlIterator = cache.urls()
    while (urlIterator.hasNext()) {
      if (urlIterator.next().startsWith("https://www.google.com/")) {
        urlIterator.remove()
      }

      "https://connect.squareup.com/robots.txt",
    )

  println("TLS1.3+TLS1.2")
  testClient(urls, buildClient(ConnectionSpec.RESTRICTED_TLS))

  println("\nTLS1.3 only")
  testClient(urls, buildClient(TLS_13))

  println("\nTLS1.3 then fallback")
  testClient(urls, buildClient(TLS_13, TLS_12))

Calls are executed in one of two ways:

 * **Synchronous:** your thread blocks until the response is readable.

    the thread's `UncaughtExceptionHandler`.
 *  Fix: Don't evict incomplete entries when iterating the cache. We had a bug where iterating
    `Cache.urls()` would prevent in-flight entries from being written.


## Version 3.14.3

_2019-09-10_

 *  Fix: Don't lose HTTP/2 flow control bytes when incoming data races with a stream close. If this

  if (result == null) {
    result = CacheControl.parse(headers)
    lazyCacheControl = result
  }
  return result
}

internal fun canonicalUrl(url: String): String {
  // Silently replace web socket URLs with HTTP URLs.
  return when {
    url.startsWith("ws:", ignoreCase = true) -> {
      "http:${url.substring(3)}"
    }
    url.startsWith("wss:", ignoreCase = true) -> {
      "https:${url.substring(4)}"
    }

     * Sets the URL target of this request.
     *
     * @throws IllegalArgumentException if [url] is not a valid HTTP or HTTPS URL. Avoid this
     *     exception by calling [HttpUrl.parse]; it returns null for invalid URLs.
     */
    open fun url(url: String): Builder {
      return url(canonicalUrl(url).toHttpUrl())
    }

    /**
     * Sets the URL target of this request.
     *

   */
  @Throws(IOException::class)
  fun evictAll() {
    cache.evictAll()
  }

  /**
   * Returns an iterator over the URLs in this cache. This iterator doesn't throw
   * `ConcurrentModificationException`, but if new responses are added while iterating, their URLs
   * will not be returned. If existing responses are evicted during iteration, they will be absent
   * (unless they were already returned).
   *