def METHOD_NAME() -> None:
    """Sets the number of model server workers used by Uvicorn in the environment variable.
    The number of model server workers will be set as WEB_CONCURRENCY in the environment
    variables.
    The default number of model server workers is the number of cores.
    The following environment variables will adjust the number of workers:
        VERTEX_CPR_WEB_CONCURRENCY:
            The number of the workers. This will overwrite the number calculated by the other
            variables, min(VERTEX_CPR_WORKERS_PER_CORE * number_of_cores, VERTEX_CPR_MAX_WORKERS).
        VERTEX_CPR_WORKERS_PER_CORE:
            The number of the workers per core. The default is 1.
        VERTEX_CPR_MAX_WORKERS:
            The maximum number of workers can be used given the value of VERTEX_CPR_WORKERS_PER_CORE
            and the number of cores.
    """
    workers_per_core_str = os.getenv("VERTEX_CPR_WORKERS_PER_CORE", "1")
    max_workers_str = os.getenv("VERTEX_CPR_MAX_WORKERS")
    use_max_workers = None
    if max_workers_str:
        use_max_workers = int(max_workers_str)
    web_concurrency_str = os.getenv("VERTEX_CPR_WEB_CONCURRENCY")
    if not web_concurrency_str:
        cores = multiprocessing.cpu_count()
        workers_per_core = float(workers_per_core_str)
        default_web_concurrency = workers_per_core * cores
        web_concurrency = max(int(default_web_concurrency), 2)
        if use_max_workers:
            web_concurrency = min(web_concurrency, use_max_workers)
        web_concurrency_str = str(web_concurrency)
    os.environ["WEB_CONCURRENCY"] = web_concurrency_str
    logging.warning(
        f'Set the number of model server workers to {os.environ["WEB_CONCURRENCY"]}.'
    )