#vulnerable code 
                                public MatrixStore<N> getInverse() {

        if (myInverse == null) {

            final MatrixStore<N> tmpQ1 = this.getQ1();
            final MatrixStore<N> tmpD = this.getD();

            final int tmpRowDim = (int) tmpD.countRows();
            final int tmpColDim = (int) tmpQ1.countRows();
            final PhysicalStore<N> tmpMtrx = this.makeZero(tmpRowDim, tmpColDim);

            double tmpSingularValue;
            final int rank = this.getRank();
            for (int i = 0; i < rank; i++) {
                tmpSingularValue = tmpD.doubleValue(i, i);
                for (int j = 0; j < tmpColDim; j++) {
                    tmpMtrx.set(i, j, tmpQ1.toScalar(j, i).conjugate().divide(tmpSingularValue).getNumber());
                }
            }

            myInverse = this.getQ2().multiply(tmpMtrx);
        }

        return myInverse;
    } 
                            #location 21 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public MatrixStore<N> getInverse() {

        return this.getInverse(this.preallocate(new Structure2D() {

            public long countRows() {
                return myTransposed ? myBidiagonal.getColDim() : myBidiagonal.getRowDim();
            }

            public long countColumns() {
                return myTransposed ? myBidiagonal.getRowDim() : myBidiagonal.getColDim();
            }
        }));
    }