public String toString() {
int ngt = piosb.numberOfGeneTrees();
String nl = System.getProperty("line.separator");
String s = nl + pioTreeAsText() + nl;
for (int g = 0; g < ngt; g++) {
s += "Gene tree " + g + nl;
s += piosb.genetreeAsText(g) + nl;
}
s += nl;
return s;
}
