ga = Graph(10,20; seed=1)
gb = Graph(10,20; seed=1)
@test sprint(show,edges(ga)) == "EdgeIter 20"
@test sprint(show, start(edges(ga))) == "EdgeIterState [1, 1, false]"

@test length(collect(edges(Graph(0,0)))) == 0

@test edges(ga) == edges(gb)
@test edges(ga) == collect(Edge, edges(gb))
@test collect(Edge, edges(gb)) == edges(ga)
@test Set{Edge}(collect(Edge, edges(gb))) == edges(ga)
@test edges(ga) == Set{Edge}(collect(Edge, edges(gb)))

@test eltype(edges(ga)) == Edge

ga = DiGraph(10,20; seed=1)
gb = DiGraph(10,20; seed=1)
@test edges(ga) == edges(gb)
@test edges(ga) == collect(Edge, edges(gb))
@test collect(Edge, edges(gb)) == edges(ga)
@test Set{Edge}(collect(Edge, edges(gb))) == edges(ga)
@test edges(ga) == Set{Edge}(collect(Edge, edges(gb)))

ga = Graph(10)
add_edge!(ga, 3, 2)
add_edge!(ga, 3, 10)
add_edge!(ga, 5, 10)
add_edge!(ga, 10, 3)

eit = edges(ga)
es = start(eit)

@test es.s == 2
@test es.di == 1

@test [e for e in eit] == [Edge(2, 3), Edge(3, 10), Edge(5,10)]

ga = DiGraph(10)
add_edge!(ga, 3, 2)
add_edge!(ga, 3, 10)
add_edge!(ga, 5, 10)
add_edge!(ga, 10, 3)

eit = edges(ga)
es = start(eit)

@test es.s == 3
@test es.di == 1

@test [e for e in eit] == [Edge(3, 2), Edge(3, 10), Edge(5,10), Edge(10,3)]
