// Proceed by binary search because comparison may be long.
protected final int getSortedIndex(DynamicNode parentNode, DynamicNode childNode) {
int lo = -1;
int hi = getChildCount(parentNode);
while (lo + 1 != hi) {
int mid = (lo + hi) / 2;
DynamicNode node = (DynamicNode) getChild(parentNode, mid);
if (childNode.compareTo(node) < 0) hi = mid;
else lo = mid;
}
return hi;
}
