Periodic ParametricSpline() does not accept an 's' argument

When trying to fit a periodic ParametricSpline() the function does not accept an s argument

Slightly modified example form the runtest.jl:
x = [23. 24. 25. 25. 24. 23.;
13. 12. 12. 13. 13. 13.]
spl = ParametricSpline(x, periodic=true,s=1)

Error message:
ERROR: KeyError: key 1 not found
Stacktrace:
[1] getindex at ./dict.jl:478 [inlined]
[2] _ParametricSpline(::Nothing, ::Array{Float64,2}, ::Nothing, ::Array{Float64,1}, ::Int64, ::Int64, ::String, ::Bool) at /home/user/.julia/packages/Dierckx/9SY4A/src/Dierckx.jl:573
[3] #ParametricSpline#5 at /home/user/.julia/packages/Dierckx/9SY4A/src/Dierckx.jl:433 [inlined]
[4] (::getfield(Core, Symbol("#kw#Type")))(::NamedTuple{(:periodic, :s),Tuple{Bool,Int64}}, ::Type{ParametricSpline}, ::Array{Float64,2}) at ./none:0
[5] top-level scope at none:0

Without s=1 or with s=0 everything works fine

Thanks for your help
Alex

Start by reproducing the periodic ParametricSpline example from the issue and inspect the ParametricSpline implementation in Dierckx.jl around line 573, along with the related example in runtest.jl. The issue is done when a periodic spline accepts a positive s argument without the KeyError while preserving the existing behavior for s=0 or no s argument.

Written by the indexing model from the issue text.