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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 rustcall(func, *args):
 """Calls rust method and does some error handling."""

    lib.semaphore_err_clear()
    rv = func(*args)
    err = lib.semaphore_err_get_last_code()
    if not err:
        return rv
    msg = lib.semaphore_err_get_last_message()
    cls = exceptions_by_code.get(err, SemaphoreError)
    exc = cls(decode_str(msg))
    backtrace = decode_str(lib.semaphore_err_get_backtrace())
    if backtrace:
        exc.rust_info = backtrace
    raise exc