cumsum on Laurent space Fun does not work

julia> f = Fun(Laurent(), [1,2,3,4])
Fun(Laurent(【0.0,6.283185307179586❫), [1, 2, 3, 4])

julia> cumsum(f)
ERROR: AssertionError: ncoefficients(f) == 0 || abs(f.coefficients[1]) < 100 * eps()
Stacktrace:
 [1] integrate(f::Fun{Taylor{PeriodicSegment{…}, ComplexF64}, Int64, SubArray{Int64, 1, Vector{…}, Tuple{…}, true}})
   @ ApproxFunFourier ~/.julia/packages/ApproxFunFourier/AYt6V/src/calculus.jl:56
 [2] cumsum(f::Fun{Taylor{PeriodicSegment{…}, ComplexF64}, Int64, SubArray{Int64, 1, Vector{…}, Tuple{…}, true}})
   @ ApproxFunBase ~/.julia/packages/ApproxFunBase/jd32s/src/Fun.jl:714
 [3] iterate
   @ ./generator.jl:47 [inlined]
 [4] _collect(c::Vector{…}, itr::Base.Generator{…}, ::Base.EltypeUnknown, isz::Base.HasShape{…})
   @ Base ./array.jl:854
 [5] collect_similar
   @ ./array.jl:763 [inlined]
 [6] map
   @ ./abstractarray.jl:3286 [inlined]
 [7] cumsum(f::Fun{ApproxFunBase.SumSpace{Tuple{…}, PeriodicSegment{…}, ComplexF64}, Int64, Vector{Int64}})
   @ ApproxFunBase ~/.julia/packages/ApproxFunBase/jd32s/src/Spaces/SumSpace.jl:312
 [8] top-level scope
   @ REPL[3]:1
Some type information was truncated. Use `show(err)` to see complete types.

julia> versioninfo()
Julia Version 1.10.10
Commit 95f30e51f41 (2025-06-27 09:51 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (x86_64-apple-darwin24.0.0)
  CPU: 16 × Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, skylake)
Threads: 16 default, 0 interactive, 8 GC (on 16 virtual cores)
Environment:
  JULIA_NUM_THREADS = 16

(jl_Yu4Eks) pkg> st
Status `/private/var/folders/kj/g4l55jh967zgr_gdj12tbjdm0000gn/T/jl_Yu4Eks/Project.toml`
  [28f2ccd6] ApproxFun v0.13.28

Not sure why this assertion error is triggered, since

julia> ncoefficients(f)
4

julia> abs(f.coefficients[1])
1

Reproduce the failure with the Laurent-space Fun example, then inspect ApproxFunFourier's calculus.jl at the reported assertion and ApproxFunBase's cumsum implementation in Fun.jl and SumSpace.jl. Done means cumsum(f) completes for this example without triggering the assertion and returns the expected cumulative function.