#vulnerable code 
                                private boolean isFeasible() {

        boolean retVal = true;

        final MatrixStore<Double> tmpAEX = this.getAEX();
        final MatrixStore<Double> tmpBE = this.getMatrixBE();
        for (int i = 0; retVal && (i < tmpBE.countRows()); i++) {
            if (options.slack.isDifferent(tmpBE.doubleValue(i), tmpAEX.doubleValue(i))) {
                retVal = false;
            }
        }

        return retVal;
    } 
                            #location 8 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private boolean isFeasible() {

        boolean retVal = true;

        final MatrixStore<Double> tmpSE = this.getSE();
        for (int i = 0; retVal && (i < tmpSE.countRows()); i++) {
            if (!options.slack.isZero(tmpSE.doubleValue(i))) {
                retVal = false;
            }
        }

        return retVal;
    }