{!> ../../docs_src/request_files/tutorial001.py!}
```

////

Using `UploadFile` has several advantages over `bytes`:

* You don't have to use `File()` in the default value of the parameter.
* It uses a "spooled" file:
    * A file stored in memory up to a maximum size limit, and after passing this limit it will be stored in disk.

    return planConnectToRoute(newRouteSelection.next(), newRouteSelection.routes)
  }

  /**
   * Returns a plan to reuse a pooled connection, or null if the pool doesn't have a connection for
   * this address.
   *
   * If [planToReplace] is non-null, this will swap it for a pooled connection if that pooled
   * connection uses HTTP/2. That results in fewer sockets overall and thus fewer TCP slow starts.
   */

  /**
   * Returns a fluent iterable that combines two iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#concat}.

  }

  /**
   * Combines two iterables into a single iterable. The returned iterable has an iterator that
   * traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *

    // If we raced another call connecting to this host, coalesce the connections. This makes for
    // 3 different lookups in the connection pool!
    val pooled3 = routePlanner.planReusePooledConnection(this, routes)
    if (pooled3 != null) return pooled3.connection

    connection.withLock {
      connectionPool.put(connection)
      user.acquireConnectionNoEvents(connection)
    }

## Version 4.4.1

_2020-03-08_

 *  Fix: Don't reuse a connection on redirect if certs match but DNS does not. For better
    locality and performance OkHttp attempts to use the same pooled connection across redirects and
    follow-ups. It independently shares connections when the IP addresses and certificates match,
    even if the host names do not. In 4.4.0 we introduced a regression where we shared a connection

  }

  /**
   * Sets the delegate of `timeout` to [Timeout.NONE] and resets its underlying timeout
   * to the default configuration. Use this to avoid unexpected sharing of timeouts between pooled
   * connections.
   */
  private fun detachTimeout(timeout: ForwardingTimeout) {
    val oldDelegate = timeout.delegate
    timeout.setDelegate(Timeout.NONE)
    oldDelegate.clearDeadline()

    "X-Amz-Request-Id": "17CDC1F4D7E69123",
    "X-Content-Type-Options": "nosniff",
    "X-Xss-Protection": "1; mode=block"
  },
  "tags": {
    "objectLocation": {
      "name": "hosts",
      "poolId": 1,
      "setId": 1,
      "drives": [
        "/mnt/data1",
        "/mnt/data2",
        "/mnt/data3",
        "/mnt/data4"
      ]
    }
  },
  "accessKey": "minioadmin"
}
```

        when {
          client.fastFallback -> FastFallbackExchangeFinder(routePlanner, client.taskRunner)
          else -> SequentialExchangeFinder(routePlanner)
        }
    }
  }

  /** Finds a new or pooled connection to carry a forthcoming request and response. */
  internal fun initExchange(chain: RealInterceptorChain): Exchange {
    this.withLock {
      check(expectMoreExchanges) { "released" }

    different cipher suite than before! OkHttp's defaults cipher suites are selected for good
    security and performance.

 *  New: `ConnectionListener` publishes events for connects, disconnects, and use of pooled
    connections.

 *  Fix: Immediately update the connection's flow control window instead of waiting for the
    receiving stream to process it.