G = Graph(10)
A = 100

for i in 1:A
    new = sample(collect(nodes(G)), 2, replace=true)
    add_arc!(G, new[1], new[2])
end

u = 1
@test in_neighbor(G, u) == keys(badj(G)[u])
@test out_neighbor(G, u) == keys(fadj(G)[u])

@test nodes(G) == keys(fadj(G))
@test length(nodes(G)) == G.nn

tes_out_neighbor = out_neighbor(G, u)
out_neighbor_arc = Arc[]
for v in tes_out_neighbor
    auv = collect(arcs(G, u, v))
    append!(out_neighbor_arc, auv)
end
@test out_neighbor_arc == collect(arcs(G, u, :))