val result = Buffer()

    while (pos < limit) {
      var dot = string.indexOf('.', startIndex = pos)
      if (dot == -1) dot = limit

      if (!encodeLabel(string, pos, dot, result)) {
        // If we couldn't encode the label, give up.
        return null
      }

      if (dot < limit) {
        result.writeByte('.'.code)
        pos = dot + 1
      } else {
        break
      }
    }

 *  Fix: Don't crash if a TLS tunnel's response body is truncated.
 *  Fix: Don't track unusable routes beyond their usefulness. We had a bug where we could track
    certain bad routes indefinitely; now we only track the ones that could be necessary.
 *  Fix: Defer proxy selection until a proxy is required. This saves calls to `ProxySelector` on
    calls that use a pooled connection.


## Version 4.3.1

   * pool when it shouldn't. Symmetrically, this must always be checked before returning a
   * connection from the pool.
   *
   * Once true this is always true. Guarded by this.
   */
  var noNewExchanges = false

  /**
   * If true, this connection may not be used for coalesced requests. These are requests that could
   * share the same connection without sharing the same hostname.

          fileToClose = file
          file = null
        }
      }

      fileToClose?.closeQuietly()
    }
  }

  companion object {
    // TODO(jwilson): what to do about timeouts? They could be different and unfortunately when any
    //     timeout is hit we like to tear down the whole stream.

    private const val SOURCE_UPSTREAM = 1
    private const val SOURCE_FILE = 2

 * of Android's private InetAddress#isNumeric API.
 *
 * This matches IPv6 addresses as a hex string containing at least one colon, and possibly
 * including dots after the first colon. It matches IPv4 addresses as strings containing only
 * decimal digits and dots. This pattern matches strings like "a:.23" and "54" that are neither IP

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3

import okio.IOException

interface Callback {
  /**
   * Called when the request could not be executed due to cancellation, a connectivity problem or
   * timeout. Because networks can fail during an exchange, it is possible that the remote server
   * accepted the request before the failure.
   */
  fun onFailure(

    assertContent("This connection won't pool properly", response1)
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Give the server time to enact the socket policy if it's one that could happen after the
    // client has received the response.
    Thread.sleep(500)
    val response2 = getResponse(newRequest("/b"))
    response1.body.source().timeout().timeout(100, TimeUnit.MILLISECONDS)

        if (toClose != null) {
          connection.connectionListener.connectionClosed(connection)
        }
      } else {
        check(toClose == null) // If we still have a connection we shouldn't be closing any sockets.
      }
    }

    val result = timeoutExit(e)
    if (e != null) {
      eventListener.callFailed(this, result!!)
    } else {
      eventListener.callEnd(this)
    }

    assertThat(url.queryParameter("a")).isEqualTo("!$(),/:;?@[]\\^`{|}~")
  }

  /**
   * When callers parse a URL with query components that aren't encoded, we shouldn't convert them
   * into a canonical form because doing so could be semantically different.
   */
  @Test
  fun queryCharactersNotReencodedWhenParsed() {
    val url = parse("http://host/?a=!$(),/:;?@[]\\^`{|}~")

        try {
          ******@****.***(removeSnapshot.key())
        } catch (_: IOException) {
          // Nothing useful to do here. We failed to remove from the cache. Most likely that's
          // because we couldn't update the journal, but the cached entry will still be gone.
        } finally {
          this.removeSnapshot = null
        }
      }
    }
  }

  /** A snapshot of the values for an entry. */