@Override
	public boolean equals(Object that) {
		boolean result = false;
		if (that instanceof TreeBipartition) {
			TreeBipartition b = (TreeBipartition) that;
			result = ingroup.size() == b.ingroup.size() && outgroup.size() == b.outgroup.size() &&
					 ingroup.containsAll(b.ingroup) && outgroup.containsAll(b.outgroup);
		}
		return result;
	}