#fixed code
                             @Override
	public List<Feature> encodeFeatures(List<String> ids, List<Feature> features, SkLearnEncoder encoder){
		int[] shape = getComponentsShape();

		int numberOfComponents = shape[0];
		int numberOfFeatures = shape[1];

		List<? extends Number> components = getComponents();
		List<? extends Number> mean = getMean();

		ClassDictUtil.checkSize(numberOfFeatures, ids, features, mean);

		Boolean whiten = getWhiten();

		List<? extends Number> explainedVariance = (whiten ? getExplainedVariance() : null);

		ClassDictUtil.checkSize(numberOfComponents, explainedVariance);

		String id = String.valueOf(PCA.SEQUENCE.getAndIncrement());

		ids.clear();

		List<Feature> result = new ArrayList<>();

		for(int i = 0; i < numberOfComponents; i++){
			List<? extends Number> component = MatrixUtil.getRow(components, numberOfComponents, numberOfFeatures, i);

			Apply apply = new Apply("sum");

			for(int j = 0; j < numberOfFeatures; j++){
				Feature feature = features.get(j);

				// "($name[i] - mean[i]) * component[i]"
				Expression expression = (feature.toContinuousFeature()).ref();

				Number meanValue = mean.get(j);
				if(!ValueUtil.isZero(meanValue)){
					expression = PMMLUtil.createApply("-", expression, PMMLUtil.createConstant(meanValue));
				}

				Number componentValue = component.get(j);
				if(!ValueUtil.isOne(componentValue)){
					expression = PMMLUtil.createApply("*", expression, PMMLUtil.createConstant(componentValue));
				}

				apply.addExpressions(expression);
			}

			if(whiten){
				Number explainedVarianceValue = explainedVariance.get(i);

				if(!ValueUtil.isOne(explainedVarianceValue)){
					apply = PMMLUtil.createApply("/", apply, PMMLUtil.createConstant(Math.sqrt(ValueUtil.asDouble(explainedVarianceValue))));
				}
			}

			DerivedField derivedField = encoder.createDerivedField(createName(id, i), apply);

			ids.add((derivedField.getName()).getValue());

			result.add(new ContinuousFeature(encoder, derivedField));
		}

		return result;
	}
#vulnerable code 
                             @Override
	public List<Feature> encodeFeatures(List<String> ids, List<Feature> features, SkLearnEncoder encoder){
		int[] shape = getComponentsShape();

		int numberOfComponents = shape[0];
		int numberOfFeatures = shape[1];

		if(ids.size() != numberOfFeatures || features.size() != numberOfFeatures){
			throw new IllegalArgumentException();
		}

		String id = String.valueOf(PCA.SEQUENCE.getAndIncrement());

		List<? extends Number> components = getComponents();
		List<? extends Number> mean = getMean();

		Boolean whiten = getWhiten();

		List<? extends Number> explainedVariance = (whiten ? getExplainedVariance() : null);

		ids.clear();

		List<Feature> result = new ArrayList<>();

		for(int i = 0; i < numberOfComponents; i++){
			List<? extends Number> component = MatrixUtil.getRow(components, numberOfComponents, numberOfFeatures, i);

			Apply apply = new Apply("sum");

			for(int j = 0; j < numberOfFeatures; j++){
				Feature feature = features.get(j);

				// "($name[i] - mean[i]) * component[i]"
				Expression expression = (feature.toContinuousFeature()).ref();

				Number meanValue = mean.get(j);
				if(!ValueUtil.isZero(meanValue)){
					expression = PMMLUtil.createApply("-", expression, PMMLUtil.createConstant(meanValue));
				}

				Number componentValue = component.get(j);
				if(!ValueUtil.isOne(componentValue)){
					expression = PMMLUtil.createApply("*", expression, PMMLUtil.createConstant(componentValue));
				}

				apply.addExpressions(expression);
			}

			if(whiten){
				Number explainedVarianceValue = explainedVariance.get(i);

				if(!ValueUtil.isOne(explainedVarianceValue)){
					apply = PMMLUtil.createApply("/", apply, PMMLUtil.createConstant(Math.sqrt(ValueUtil.asDouble(explainedVarianceValue))));
				}
			}

			DerivedField derivedField = encoder.createDerivedField(createName(id, i), apply);

			ids.add((derivedField.getName()).getValue());

			result.add(new ContinuousFeature(encoder, derivedField));
		}

		return result;
	} 
                            #location 19 
                            #vulnerability type NULL_DEREFERENCE