anchor.diff:  
       call test_linearization_error(success)
       call test_segment_intersection(success)
  +    call test_newton_refine_intersect(success)
   
     end subroutine curve_intersection_all_tests
   
  
positive.code: 
    end subroutine test_segment_intersection
  
  end module test_curve_intersection
  
negative.code: module test_curve_intersection
  
    use iso_c_binding, only: c_bool, c_double
    use curve, only: evaluate_multi, subdivide_nodes
    use curve_intersection, only: &
         linearization_error, segment_intersection, newton_refine_intersect
    use types, only: dp
    use unit_test_helpers, only: print_status
    implicit none
    private &
         test_linearization_error, test_segment_intersection, &
         test_newton_refine_intersect
    public curve_intersection_all_tests
  
  contains
  