@testset "Schottky null" begin
    τ = [0.40243+0.68413im -0.18138+0.21894im 0.24323-0.13416im 0.00403+0.05085im -0.31818+0.14383im; -0.18137+0.21894im 0.27914+1.01836im -0.09799+0.46222im -0.06566+0.60959im -0.14647+0.37006im; 0.24323-0.13416im -0.09799+0.46222im 0.16663+0.68136im -0.28606+0.02038im 0.18558-0.15061im; 0.00403+0.05085im -0.06566+0.60959im -0.28606+0.02038im 0.04136+1.40560im 0.19025+0.82885im; -0.31818+0.14384im -0.14647+0.37006im 0.18558-0.15061im 0.19025+0.82885im 0.74873+1.01168im ];
    R = RiemannMatrix(τ);
    z = zeros(5);
    @test min_even_theta_char(R) == [[1,0,0,1,0],[1,0,1,1,0]]
    @test hessian(z,R) ≈ hessian(z,τ) atol=1e-3
    @test hessian(z,R, [[1,0,0,1,0],[1,0,1,1,0]])[1,1] ≈ -2.79665+5.29764im atol=1e-3
    @test schottky_null(R) ≈ schottky_null(τ) atol=1e-3
end
