### Question:
InSlopeRule extends AbstractRule { @Override public boolean isSatisfied(int index, TradingRecord tradingRecord) { DifferenceIndicator diff = new DifferenceIndicator(ref, prev); Num val = diff.getValue(index); boolean minSlopeSatisfied = minSlope.isNaN() || val.isGreaterThanOrEqual(minSlope); boolean maxSlopeSatisfied = maxSlope.isNaN() || val.isLessThanOrEqual(maxSlope); boolean isNaN = minSlope.isNaN() && maxSlope.isNaN(); final boolean satisfied = minSlopeSatisfied && maxSlopeSatisfied && !isNaN; traceIsSatisfied(index, satisfied); return satisfied; } InSlopeRule(Indicator<Num> ref, Num minSlope);  InSlopeRule(Indicator<Num> ref, Num minSlope, Num maxSlope);  InSlopeRule(Indicator<Num> ref, int nthPrevious, Num maxSlope);  InSlopeRule(Indicator<Num> ref, int nthPrevious, Num minSlope, Num maxSlope); @Override boolean isSatisfied(int index, TradingRecord tradingRecord);  }### Answer:
@Test public void isSatisfied() { assertFalse(rulePositiveSlope.isSatisfied(0)); assertTrue(rulePositiveSlope.isSatisfied(1)); assertFalse(rulePositiveSlope.isSatisfied(2)); assertFalse(rulePositiveSlope.isSatisfied(9)); assertFalse(ruleNegativeSlope.isSatisfied(0)); assertFalse(ruleNegativeSlope.isSatisfied(1)); assertTrue(ruleNegativeSlope.isSatisfied(5)); assertFalse(ruleNegativeSlope.isSatisfied(9)); }