### Question:
EfficientCoverageMap implements CoverageMap { @Override public int[] computeGainsOfFixedParameter(int[] combination) { Preconditions.notNull(combination, COMBINATION_NOT_NULL); int[] gains = new int[fixedParameterSize]; Set<ParameterCombinationCoverageMap> relevantCombinations = getRelevantCombinationCoverages(combination); for (ParameterCombinationCoverageMap combinationCoverage : relevantCombinations) { combinationCoverage.addGainsOfFixedParameter(combination, gains); } return gains; } EfficientCoverageMap(Collection<IntSet> parameterCombinations, int fixedParameter, Int2IntMap parameters,
                                ConstraintChecker constraintChecker); @Override boolean mayHaveUncoveredCombinations(); @Override void markAsCovered(int[] combination); @Override int[] computeGainsOfFixedParameter(int[] combination); @Override Optional<int[]> getUncoveredCombination();  }### Answer:
@Test void gainsZeroIfAllCombinationsCovered() { EfficientCoverageMap coverageMap = noUncoveredCoverageMap(); int[] partialCombination = new int[]{0, -1}; int[] gains = coverageMap.computeGainsOfFixedParameter(partialCombination); assertEquals(2, gains.length); assertEquals(0, gains[0]); assertEquals(0, gains[1]); }