```

////

//// tab | Python 3.10+ non-Annotated

/// tip | "提示"

Prefer to use the `Annotated` version if possible.

///

```Python
{!> ../../docs_src/app_testing/app_b_py310/main.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip | "提示"

Prefer to use the `Annotated` version if possible.

///

```Python

			// Any concurrency less than '4' just stick to '4' concurrent
			// operations for now to begin with.
			if concurrency < 4 {
				concurrency = 4
			}

			// if GOMAXPROCS is set to a lower value then choose to use
			// concurrency == GOMAXPROCS instead.
			if runtime.GOMAXPROCS(0) < concurrency {
				concurrency = runtime.GOMAXPROCS(0)
			}
		}

		throughputHighestGet := uint64(0)
		throughputHighestPut := uint64(0)

-		  && __string2_1bptr_p (src) && n <= 8			      \
-		  ? __mempcpy_small (dest, __mempcpy_args (src), n)	      \
-		  : __mempcpy (dest, src, n)))
-#   endif
-/* In glibc we use this function frequently but for namespace reasons
-   we have to use the name `__mempcpy'.  */
-#   define mempcpy(dest, src, n) __mempcpy (dest, src, n)
-#  endif
-
-#  if !__GNUC_PREREQ (3, 0) || defined _FORCE_INLINES
-#   if _STRING_ARCH_unaligned

All the data validation is performed under the hood by <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a>, so you get all the benefits from it. And you know you are in good hands.

You can use the same type declarations with `str`, `float`, `bool` and many other complex data types.

Several of these are explored in the next chapters of the tutorial.

## Order matters

     * field should be used for calculating that. This would likely be zero
     * but an implemantation that encorporates the transport header(for
     * efficiency) might use a different initial bufferIndex. For example,
     * to eliminate copying data when writing NbtSession data one might
     * manage that 4 byte header specifically and therefore the initial

/*
 * Copyright (C) 2014 Square, 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,

/*
 * Copyright (C) 2013 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) 2014 Square, 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,

/*
 * Copyright (C) 2014 Square, 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,

/*
 * Copyright (C) 2020 Square, 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,