def union_overlapping(intervals):
  """Union any overlapping intervals in the given set."""
  disjoint_intervals = []

  for interval in intervals:
    if disjoint_intervals and disjoint_intervals[-1].overlaps(interval):
      disjoint_intervals[-1] = disjoint_intervals[-1].union(interval)
    else:
      disjoint_intervals.append(interval)

  return disjoint_intervals