How to use the slepc4py.SLEPc.EPS.ProblemType.GNHEP function in slepc4py

value = wrapping.get_default_linear_solver()
                    if hasattr(ksp.getPC(), "setFactorSolverType"):  # PETSc >= 3.9
                        ksp.getPC().setFactorSolverType(value)
                    else:
                        ksp.getPC().setFactorSolverPackage(value)
                elif key == "maximum_iterations":
                    eps_tolerances[1] = value
                elif key == "problem_type":
                    if value == "hermitian":
                        self.eps.setProblemType(SLEPc.EPS.ProblemType.HEP)
                    elif value == "non_hermitian":
                        self.eps.setProblemType(SLEPc.EPS.ProblemType.NHEP)
                    elif value == "gen_hermitian":
                        self.eps.setProblemType(SLEPc.EPS.ProblemType.GHEP)
                    elif value == "gen_non_hermitian":
                        self.eps.setProblemType(SLEPc.EPS.ProblemType.GNHEP)
                    elif value == "pos_gen_non_hermitian":
                        self.eps.setProblemType(SLEPc.EPS.ProblemType.PGNHEP)
                    else:
                        raise RuntimeError("Invalid problem type")
                elif key == "solver":
                    if value == "power":
                        self.eps.setType(SLEPc.EPS.Type.POWER)
                    elif value == "subspace":
                        self.eps.setType(SLEPc.EPS.Type.SUBSPACE)
                    elif value == "arnoldi":
                        self.eps.setType(SLEPc.EPS.Type.ARNOLDI)
                    elif value == "lanczos":
                        self.eps.setType(SLEPc.EPS.Type.LANCZOS)
                    elif value == "krylov-schur":
                        self.eps.setType(SLEPc.EPS.Type.KRYLOVSCHUR)
                    elif value == "lapack":

def solve(self):
        """Solve for the modes of the structure.

        Notes
        -----
        This function is run on all nodes.
        """
        if(self.verbose and NOT_PARALLEL):
            info_message('Solving...')

        # Setup the solve options. We are solving a generalized non-hermitian
        # eigenvalue problem (GNHEP)
        self._solver.setOperators(self._A, self._B)
        self._solver.setProblemType(SLEPc.EPS.ProblemType.GNHEP)
        self._solver.setDimensions(self.neigs, PETSc.DECIDE)
        self._solver.setTarget(self.n0) # "guess" for effective index
        self._solver.setFromOptions()

        # Solve Ax=nBx using SLEPc.
        # Internally, we use a direct solve (MUMPS) to handle the heavy
        # lifting.
        self._solver.solve()
        nconv = self._solver.getConverged()

        if(nconv < self.neigs):
            warning_message('%d eigenmodes were requested, however only %d ' \
                            'eigenmodes were found.' % (self.neigs, nconv), \
                            module='emopt.modes')

        # nconv can be bigger than the desired number of eigen values