} else return null;
}
}
/* Apply a strategy for avoiding walking too far, either soft (weight increases) or hard limiting (pruning). */
if (s1.weHaveWalkedTooFar(options)) {
// if we're using a soft walk-limit
if( options.softWalkLimiting ){
// just slap a penalty for the overage onto s1
weight += calculateOverageWeight(s0.getWalkDistance(), s1.getWalkDistance(),