code: func ProxCmp(a, x, y interface{}) int {
  	return proxCmp(ToBytes(a), ToBytes(x), ToBytes(y))
  }
docs: // ProxCmp compares the distances a->target and b->target.
  // Returns -1 if a is closer to target, 1 if b is closer to target
  // and 0 if they are equal.