anchor.diff:    use iso_c_binding, only: c_bool, c_double
     use curve, only: &
          evaluate_curve_barycentric, evaluate_multi, specialize_curve, &
  -       evaluate_hodograph, subdivide_nodes
  +       evaluate_hodograph, subdivide_nodes, newton_refine
     use types, only: dp
     use unit_test_helpers, only: print_status, get_random_nodes, binary_round
     implicit none
     private &
          test_evaluate_curve_barycentric, test_evaluate_multi, &
          test_specialize_curve, test_evaluate_hodograph, test_subdivide_nodes, &
  -       subdivide_points_check
  +       subdivide_points_check, test_newton_refine
     public curve_all_tests
   
   contains
  
positive.code: 
    end subroutine subdivide_points_check
  
  end module test_curve
  
negative.code:     call test_specialize_curve(success)
      call test_evaluate_hodograph(success)
      call test_subdivide_nodes(success)
      call test_newton_refine(success)
  
    end subroutine curve_all_tests
  
  