@testset "Katz" begin
    g5 = DiGraph(4)
    add_edge!(g5,1,2); add_edge!(g5,2,3); add_edge!(g5,1,3); add_edge!(g5,3,4)
    for g in testdigraphs(g5)
        z = @inferred(katz_centrality(g, 0.4))
        @test round.(z, 2) == [0.32, 0.44, 0.62, 0.56]
    end
end
