We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003_py39.py hl[16,19] *}

Here we are simulating the expensive *startup* operation of loading the model by putting the (fake) model function in the dictionary with machine learning models before the `yield`. This code will be executed **before** the application **starts taking requests**, during the *startup*.

## HTTP Trace

HTTP tracing can be enabled by using [`mc admin trace`](https://docs.min.io/community/minio-object-store/reference/minio-mc-admin/mc-admin-trace.html) command.

Example:

```sh
minio server /data
```

//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

// Code generated by avx512test. DO NOT EDIT.

#include "../../../../../../runtime/textflag.h"

TEXT asmtest_avx512_ifma(SB), NOSPLIT, $0
	VPMADD52HUQ X7, X11, K1, X18                       // 62e2a509b5d7
	VPMADD52HUQ X0, X11, K1, X18                       // 62e2a509b5d0
	VPMADD52HUQ 17(SP)(BP*2), X11, K1, X18             // 62e2a509b5946c11000000
	VPMADD52HUQ -7(DI)(R8*4), X11, K1, X18             // 62a2a509b59487f9ffffff

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,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

            // Fill buffer with non-zero values
            Arrays.fill(buffer, (byte) 0xFF);

            lock.encode(buffer, 0);

            // Reserved field bytes are not modified by the encode method
            // The implementation just skips these bytes without writing zeros
            assertEquals(-1, SMBUtil.readInt4(buffer, 20));
        }
    }

    @Nested