guava/src/com/google/common/collect/ImmutableRangeSet.java
public static <E extends Comparable<? super E>>
      Collector<Range<E>, ?, ImmutableRangeSet<E>> toImmutableRangeSet() {
    return CollectCollectors.toImmutableRangeSet();
  }
public static <E extends Comparable<? super E>>
      Collector<Range<E>, ?, ImmutableRangeSet<E>> toImmutableRangeSet() {
    return CollectCollectors.toImmutableRangeSet();
  }
Returns a {@code Collector} that accumulates the input elements into a new {@code
ImmutableRangeSet}. As in {@link Builder}, overlapping ranges are not permitted and adjacent
ranges will be merged.

@since 23.1