code: public DenseMatrix solve(DenseMatrix B) throws MatrixNotSPDException {
          if (notspd)
              throw new MatrixNotSPDException();
          if (B.numRows() != n)
              throw new IllegalArgumentException("B.numRows() != n");
  
          intW info = new intW(0);
          if (upper)
              LAPACK.getInstance().dpbtrs(UpLo.Upper.netlib(), n, kd,
                      B.numColumns(), Cu.getData(), Matrices.ld(kd + 1),
                      B.getData(), Matrices.ld(n), info);
          else
              LAPACK.getInstance().dpbtrs(UpLo.Lower.netlib(), n, kd,
                      B.numColumns(), Cl.getData(), Matrices.ld(kd + 1),
                      B.getData(), Matrices.ld(n), info);
  
          if (info.val < 0)
              throw new IllegalArgumentException();
  
          return B;
      }
docs: Computes <code>A\B</code>, overwriting <code>B</code>