private function ceilComparison(UnitCandidate $a, UnitCandidate $b, $property, $quantity)
    {
        if ($a->{$property} >= $quantity && $b->{$property} < $quantity) {
            return -1;
        }
        if ($a->{$property} < $quantity && $b->{$property} >= $quantity) {
            return 1;
        }

        return false;
    }
private function ceilComparison(UnitCandidate $a, UnitCandidate $b, $property, $quantity)
    {
        if ($a->{$property} >= $quantity && $b->{$property} < $quantity) {
            return -1;
        }
        if ($a->{$property} < $quantity && $b->{$property} >= $quantity) {
            return 1;
        }

        return false;
    }
Returns -1 if A's property is greater than or equal quantity but not B.
Returns 1 if B's property is greater than or equal quantity but not A.
Else returns false.

@param UnitCandidate $a
@param UnitCandidate $b
@param string        $property
@param float         $quantity

@return bool|int