}

  /**
   * Maximum allowed false positive probability of detecting a hash flooding attack given random
   * input.
   */
  @VisibleForTesting(
      )
  static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.LinkedHashSet based
   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;

  }

  @GwtIncompatible // Chars.fromByteArray, Chars.toByteArray
  public void testByteArrayRoundTripsFails() {
    assertThrows(IllegalArgumentException.class, () -> Chars.fromByteArray(new byte[] {0x11}));
  }

  public void testEnsureCapacity() {
    assertThat(Chars.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Chars.ensureCapacity(ARRAY1, 0, 1)).isSameInstanceAs(ARRAY1);

        @DisplayName("Should handle different session keys")
        void testDifferentSessionKeys() throws GeneralSecurityException {
            byte[] sessionKey1 = new byte[16];
            Arrays.fill(sessionKey1, (byte) 0x11);

            byte[] sessionKey2 = new byte[16];
            Arrays.fill(sessionKey2, (byte) 0x22);

            Smb2SigningDigest digest1 = new Smb2SigningDigest(sessionKey1, Smb2Constants.SMB2_DIALECT_0202, null);

  /**
   * Maximum allowed false positive probability of detecting a hash flooding attack given random
   * input.
   */
  @VisibleForTesting(
      )
  static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.LinkedHashMap-based
   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;

```

### Include the `APIRouter`s for `users` and `items` { #include-the-apirouters-for-users-and-items }

Now, let's include the `router`s from the submodules `users` and `items`:

```Python hl_lines="10-11" title="app/main.py"
{!../../docs_src/bigger_applications/app/main.py!}
```

/// info

`users.router` contains the `APIRouter` inside of the file `app/routers/users.py`.

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// This package computes the exported API of a set of Go packages.
// It is only a test, not a command, nor a usefully importable package.

package main

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"go/ast"
	"go/build"
	"go/parser"
	"go/token"
	"go/types"

	CBZW R15, -1(PC)                           // efffff34
	CBZ R1, -1(PC)                             // e1ffffb4
	CCMN MI, ZR, R1, $4                        // e44341ba
	CCMNW AL, R26, $20, $11                    // 4beb543a
	CCMN PL, R24, $6, $1                       // 015b46ba
	CCMNW EQ, R20, R6, $6                      // 8602463a
	CCMN LE, R30, R12, $6                      // c6d34cba

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * 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,

  /**
   * Maximum allowed false positive probability of detecting a hash flooding attack given random
   * input.
   */
  @VisibleForTesting(
      )
  static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.LinkedHashMap-based
   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;