UtilsForCollections.java

public static Set<Integer> toSet(int[] array) {
    return Arrays.stream(array).boxed().collect(Collectors.toSet());
}
public static Set<Long> toSet(long[] array) {
    return Arrays.stream(array).boxed().collect(Collectors.toSet());
}
public static Set<Double> toSet(double[] array) {
    return Arrays.stream(array).boxed().collect(Collectors.toSet());
}