put(range, value);
      return;
    }

    Range<K> coalescedRange = coalescedRange(range, checkNotNull(value));
    put(coalescedRange, value);
  }

  /** Computes the coalesced range for the given range+value - does not mutate the map. */
  private Range<K> coalescedRange(Range<K> range, V value) {
    Range<K> coalescedRange = range;
    Entry<Cut<K>, RangeMapEntry<K, V>> lowerEntry =