address: Address,
    call: RealCall,
    routes: List<Route>?,
    requireMultiplexed: Boolean,
  ): RealConnection? {
    for (connection in connections) {
      // In the first synchronized block, acquire the connection if it can satisfy this call.
      val acquired =
        connection.withLock {
          when {
            requireMultiplexed && !connection.isMultiplexed -> {
              false
            }

 * SMB tree connections and their lifecycle.
 *
 * @author mbechler
 */
public interface SmbTreeHandleInternal extends SmbTreeHandle {

    /**
     * Releases this tree handle back to the pool for reuse
     */
    void release();

    /**
     * Ensures that DFS referrals have been resolved for this tree
     * @throws SmbException if an SMB-specific error occurs

			return &k.PublicKey
		case *ecdsa.PrivateKey:
			return &k.PublicKey
		default:
			return nil
		}
	}

	pemBlockForKey := func(priv any) *pem.Block {
		switch k := priv.(type) {
		case *rsa.PrivateKey:
			return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}
		case *ecdsa.PrivateKey:
			b, err := x509.MarshalECPrivateKey(k)
			if err != nil {

  export TFCI_BUILD_PIP_PACKAGE_ADDITIONAL_WHEEL_NAMES="$(echo $TFCI_BUILD_PIP_PACKAGE_ADDITIONAL_WHEEL_NAMES | sed 's/tensorflow/tf_nightly/g')"
fi

# TODO(b/361369076) Remove the following block after TF NumPy 1 is dropped
# Move hermetic requirement lock files for NumPy 1 to the root
if [[ "$TFCI_WHL_NUMPY_VERSION" == 1 ]]; then
  cp ./ci/official/requirements_updater/numpy1_requirements/*.txt .
fi

    ListenableFuture<Boolean> future2 =
        serializer.submit(blockingCallable::isRunning, directExecutor());

    // Wait for the first task to be started in the background. It will block until we explicitly
    // stop it.
    blockingCallable.waitForStart();

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    assertThat(future2.isDone()).isFalse();

					write([]byte(err.Error()))
				} else {
					write([]byte{0})
				}
				xioutil.SafeClose(doneCh)
				return
			case block := <-blockCh:
				var tmp [5]byte
				tmp[0] = 2
				binary.LittleEndian.PutUint32(tmp[1:], uint32(len(block)))
				write(tmp[:])
				write(block)
				if canWrite {
					xhttp.Flush(w)
				}
			}
		}
	}()
	return &h
}

Let's use the tools provided by **FastAPI** to handle security.

## How it looks { #how-it-looks }

Let's first just use the code and see how it works, and then we'll come back to understand what's happening.

## Create `main.py` { #create-main-py }

Copy the example in a file `main.py`:

{* ../../docs_src/security/tutorial001_an_py310.py *}

## Run it { #run-it }

/// info

      val blank = readUtf8LineStrict()

      if (MAGIC != magic ||
        VERSION_1 != version ||
        appVersion.toString() != appVersionString ||
        valueCount.toString() != valueCountString ||
        blank.isNotEmpty()
      ) {
        throw IOException(
          "unexpected journal header: [$magic, $version, $valueCountString, $blank]",
        )
      }

type UserRequest struct {
	URL     string      `json:"url"`
	Headers http.Header `json:"headers"`
}

// GetObjectContext provides the necessary details to perform
// download of the object, and return back the processed response
// to the server.
type GetObjectContext struct {
	OutputRoute string `json:"outputRoute"`
	OutputToken string `json:"outputToken"`
	InputS3URL  string `json:"inputS3Url"`
}

/*
 * Copyright (C) 2025 Block, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,