@testset "bigfloat initial convergence #720" begin
    f(x) = x[1]^2
    x0 = BigFloat[0]
    obj = OnceDifferentiable(f, x0; autodiff = :forward)
    for method in (
        GradientDescent,
        BFGS,
        LBFGS,
        AcceleratedGradientDescent,
        MomentumGradientDescent,
        ConjugateGradient,
        Newton,
        NewtonTrustRegion,
        SimulatedAnnealing,
    )
        result = Optim.optimize(f, x0, method())
    end
end
