anchor.diff:  
     end subroutine bbox
   
  -  subroutine specialize_curve( &
  +  subroutine specialize_curve_generic( &
          nodes, degree, dimension_, start, end_, curve_start, curve_end, &
          new_nodes, true_start, true_end)
  +
  +    ! NOTE: This is a helper for ``specialize_curve`` that works on any degree.
   
       !f2py integer intent(hide), depend(nodes) :: dimension_ = size(nodes, 2)
       real(dp), intent(in) :: nodes(degree + 1, dimension_)
  
positive.code:     true_start = curve_start + start * interval_delta
      true_end = curve_start + end_ * interval_delta
  
    end subroutine specialize_curve
  
  end module speedup
  
negative.code:   public de_casteljau_one_round, evaluate_multi, linearization_error, &
           evaluate_barycentric, evaluate_barycentric_multi, &
           evaluate_cartesian_multi, cross_product, segment_intersection, &
           bbox, specialize_curve_generic, specialize_curve
  
    ! NOTE: This still relies on .f2py_f2cmap being present
    !       in the directory that build is called from.
  