return err
	}
	key, err := hex.DecodeString(keyHex[8:])
	if err != nil {
		return err
	}
	// Verify that CRC is ok.
	want := binary.LittleEndian.Uint32(id)
	got := crc32.ChecksumIEEE(key)
	if want != got {
		return fmt.Errorf("Invalid key checksum, want %x, got %x", want, got)
	}

	stream, err := sio.AES_256_GCM.Stream(key)
	if err != nil {
		return err
	}

# Testing Dependencies with Overrides

## Overriding dependencies during testing

There are some scenarios where you might want to override a dependency during testing.

You don't want the original dependency to run (nor any of the sub-dependencies it might have).

	for i, v := range vectors {
		r := strings.NewReader(v.in)
		got, err := parsePAX(r)
		if !maps.Equal(got, v.want) && !(len(got) == 0 && len(v.want) == 0) {
			t.Errorf("test %d, parsePAX():\ngot  %v\nwant %v", i, got, v.want)
		}
		if ok := err == nil; ok != v.ok {
			t.Errorf("test %d, parsePAX(): got %v, want %v", i, ok, v.ok)
		}
	}
}

func TestReadOldGNUSparseMap(t *testing.T) {

				input[key] = ss
			}

			err := sw.PrintAll(input)
			if tt.wantErr {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
			}
			want, _ := os.ReadFile(tt.want)
			if err := util.Compare(got.Bytes(), want); err != nil {
				t.Error(err)
			}
		})
	}
}

const clientConfigType = "type.googleapis.com/envoy.service.status.v3.ClientConfig"

And it shows their true commitment to FastAPI and its **community** (you), as they not only want to provide you a **good learning experience** but also want to make sure you have a **good and healthy framework**, FastAPI. 🙇

You might want to try their courses:

* <a href="https://training.talkpython.fm/fastapi-courses" class="external-link" target="_blank">Talk Python Training</a>

///

## Previous Steps Before Starting

There are many cases where you want to perform some steps **before starting** your application.

For example, you might want to run **database migrations**.

But in most cases, you will want to perform these steps only **once**.

So, you will want to have a **single process** to perform those **previous steps**, before starting the application.

			t.Errorf("Test%d (%s): Size  got %d , want %d", i+1, test.name, actualSize, test.expectedCompletedSize)
		}
		if repStatusStr := rinfos.ReplicationStatusInternal(); repStatusStr != test.expectedReplicationStatusInternal {
			t.Errorf("Test%d (%s): Internal replication status  got %s , want %s", i+1, test.name, repStatusStr, test.expectedReplicationStatusInternal)
		}

  - "bar"
`,
			},
			want: []string{"foo", "bar"},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if err := yaml.Unmarshal([]byte(tt.args.yamlStr), &tt.b); (err != nil) != tt.wantErr {
				t.Errorf("UnmarshalYAML() error = %v, wantErr %v", err, tt.wantErr)
			}
			if !slices.Equal(tt.b.Prefix.F(), tt.want) {
				t.Errorf("UnmarshalYAML() = %v, want %v", tt.b.Prefix.F(), tt.want)
			}
		})
	}

		tests = append(tests, testCase{in: fmt.Sprintf("%x", i), want: i})
	}
	for _, tt := range tests {
		got, err := parseHexUint([]byte(tt.in))
		if tt.wantErr != "" {
			if err != nil && !strings.Contains(err.Error(), tt.wantErr) {
				t.Errorf("parseHexUint(%q) = %v, %v; want error %q", tt.in, got, err, tt.wantErr)
			}
		} else {
			if err != nil || got != tt.want {

		}

		rResources[i] = arg.Resources[0]
	}
	if len(l.lockMap) != len(rResources)+len(wResources) {
		t.Fatalf("lockmap len, got %d, want %d + %d", len(l.lockMap), len(rResources), len(wResources))
	}
	if len(l.lockUID) != len(rResources)+len(wResources) {
		t.Fatalf("lockUID len, got %d, want %d + %d", len(l.lockUID), len(rResources), len(wResources))
	}
	// Expire an hour from now, should keep all
	l.expireOldLocks(time.Hour)