initialize(dealii::MatrixFree< dim, Number > const &matrix_free_in, unsigned int const dof_index_vector_in, unsigned int const dof_index_scalar_in, unsigned int const quad_index_in, Structure::ElasticityOperatorBase< dim, Number > const &elasticity_operator_base_in) (defined in ExaDG::MaxPrincipalStressCalculator< dim, Number >)