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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def fork_processes(num_processes: Optional[int], max_restarts: int = None) -> int: """Starts multiple worker processes. If ``num_processes`` is None or <= 0, we detect the number of cores available on this machine and fork that number of child processes. If ``num_processes`` is given and > 0, we fork that specific number of sub-processes. Since we use processes and not threads, there is no shared memory between any server code. Note that multiple processes are not compatible with the autoreload module (or the ``autoreload=True`` option to `tornado.web.Application` which defaults to True when ``debug=True``). When using multiple processes, no IOLoops can be created or referenced until after the call to ``fork_processes``. In each child process, ``fork_processes`` returns its *task id*, a number between 0 and ``num_processes``. Processes that exit abnormally (due to a signal or non-zero exit status) are restarted with the same id (up to ``max_restarts`` times). In the parent process, ``fork_processes`` returns None if all child processes have exited normally, but will otherwise only exit by throwing an exception. max_restarts defaults to 100. Availability: Unix """

    if max_restarts is None:
        max_restarts = 100

    global _task_id
    assert _task_id is None
    if num_processes is None or num_processes <= 0:
        num_processes = cpu_count()
    gen_log.info("Starting %d processes", num_processes)
    children = {}

    def start_child(i: int) -> Optional[int]:
        pid = os.fork()
        if pid == 0:
            # child process
            _reseed_random()
            global _task_id
            _task_id = i
            return i
        else:
            children[pid] = i
            return None

    for i in range(num_processes):
        id = start_child(i)
        if id is not None:
            return id
    num_restarts = 0
    while children:
        try:
            pid, status = os.wait()
        except OSError as e:
            if errno_from_exception(e) == errno.EINTR:
                continue
            raise
        if pid not in children:
            continue
        id = children.pop(pid)
        if os.WIFSIGNALED(status):
            gen_log.warning(
                "child %d (pid %d) killed by signal %d, restarting",
                id,
                pid,
                os.WTERMSIG(status),
            )
        elif os.WEXITSTATUS(status) != 0:
            gen_log.warning(
                "child %d (pid %d) exited with status %d, restarting",
                id,
                pid,
                os.WEXITSTATUS(status),
            )
        else:
            gen_log.info("child %d (pid %d) exited normally", id, pid)
            continue
        num_restarts += 1
        if num_restarts > max_restarts:
            raise RuntimeError("Too many child restarts, giving up")
        new_id = start_child(id)
        if new_id is not None:
            return new_id
    # All child processes exited cleanly, so exit the master process
    # instead of just returning to right after the call to
    # fork_processes (which will probably just start up another IOLoop
    # unless the caller checks the return value).
    sys.exit(0)