presto-main/src/main/java/io/prestosql/execution/MemoryRevokingScheduler.java/MemoryRevokingScheduler/checkFraction
class MemoryRevokingScheduler:    private static double checkFraction(double value, String valueName)
    {
        requireNonNull(valueName, "valueName is null");
        checkArgument(0 <= value && value <= 1, "%s should be within [0, 1] range, got %s", valueName, value);
        return value;
    }