### Question:
Range implements Serializable { public static Range expand(Range range, double lowerMargin, double upperMargin) { if (range == null) { throw new IllegalArgumentException("Null 'range' argument."); } double length = range.getLength(); double lower = range.getLowerBound() - length * lowerMargin; double upper = range.getUpperBound() + length * upperMargin; if (lower > upper) { lower = lower / 2.0 + upper / 2.0; upper = lower; } return new Range(lower, upper); } 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 testExpand() { Range r1 = new Range(0.0, 100.0); Range r2 = Range.expand(r1, 0.10, 0.10); assertEquals(-10.0, r2.getLowerBound(), 0.001); assertEquals(110.0, r2.getUpperBound(), 0.001); r2 = Range.expand(r1, 0.0, 0.0); assertEquals(r1, r2); try { Range.expand(null, 0.1, 0.1); fail("Null value is accepted"); } catch (Exception e) { } r2 = Range.expand(r1, -0.8, -0.5); assertEquals(65.0, r2.getLowerBound(), 0.001); assertEquals(65.0, r2.getUpperBound(), 0.001); }