### Question:
Range implements Serializable { public static Range scale(Range base, double factor) { ParamChecks.nullNotPermitted(base, "base"); if (factor < 0) { throw new IllegalArgumentException("Negative 'factor' argument."); } return new Range(base.getLowerBound() * factor, base.getUpperBound() * factor); } Range(double lower, double upper); double getLowerBound(); double getUpperBound(); double getLength(); double getCentralValue(); boolean contains(double value); boolean intersects(double b0, double b1); boolean intersects(Range range); double constrain(double value); static Range combine(Range range1, Range range2); static Range combineIgnoringNaN(Range range1, Range range2); static Range expandToInclude(Range range, double value); static Range expand(Range range,
                               double lowerMargin, double upperMargin); static Range shift(Range base, double delta); static Range shift(Range base, double delta,
                              boolean allowZeroCrossing); static Range scale(Range base, double factor); @Override boolean equals(Object obj); boolean isNaNRange(); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testScale() { Range r1 = new Range(0.0, 100.0); Range r2 = Range.scale(r1, 0.10); assertEquals(0.0, r2.getLowerBound(), 0.001); assertEquals(10.0, r2.getUpperBound(), 0.001); r1 = new Range(-10.0, 100.0); r2 = Range.scale(r1, 2.0); assertEquals(-20.0, r2.getLowerBound(), 0.001); assertEquals(200.0, r2.getUpperBound(), 0.001); r2 = Range.scale(r1, 1.0); assertEquals(r1, r2); try { Range.scale(null, 0.1); fail("Null value is accepted"); } catch (Exception e) { } try { Range.scale(r1, -0.5); fail("Negative factor accepted"); } catch (Exception e) { } }