message: Make PAIntegrator inherit from Operator instead of MFIntegrator.
diff: @@ -54,16 +54,26 @@ struct PAOperator
  #endif
  /** This class represent a partially assembled operator using libCEED.*/
  -class PAIntegrator : public MFIntegrator
  +class PAIntegrator : public Operator
  {
  #ifdef MFEM_USE_CEED
  protected:
  + CeedBasis basis, mesh_basis;
  + CeedElemRestriction restr, mesh_restr, restr_i;
  + CeedQFunction build_qfunc, apply_qfunc;
  + CeedVector node_coords, qdata;
  + Coefficient *coeff;
  + CeedQFunctionContext build_ctx;
  CeedOperator build_oper;
  - CeedQFunction build_qfunc;
  public:
  PAIntegrator()
  - : MFIntegrator(), build_oper(nullptr), build_qfunc(nullptr) { }
  + : Operator(), basis(nullptr), mesh_basis(nullptr),
  + restr(nullptr), mesh_restr(nullptr),
  + restr_i(nullptr),
  + build_qfunc(nullptr), apply_qfunc(nullptr), node_coords(nullptr),
  + qdata(nullptr), coeff(nullptr), build_ctx(nullptr), build_oper(nullptr)
  + { }
  /** This method initializes the PAIntegrator with the given CeedOperatorInfo
  @a info, an mfem::FiniteElementSpace @a fes, an mfem::IntegrationRule
  