code: public static <T> ToIntFunction<T> toIntFunction(CheckedToIntFunction<T> function) {
          return toIntFunction(function, THROWABLE_TO_RUNTIME_EXCEPTION);
      }
docs: Wrap a {@link CheckedToIntFunction} in a {@link ToIntFunction}.
  <p>
  Example:
  <code><pre>
  map.computeIfAbsent("key", Unchecked.toIntFunction(k -> {
  if (k.length() > 10)
  throw new Exception("Only short strings allowed");
  
  return 42;
  }));
  </pre></code>