def test_ws_retrieve_data_on_input_ports():
pg = PortGraph()
pg.add_vertex(0)
pg.add_out_port(0, "out", 0)
pg.add_vertex(1)
pg.add_in_port(1, "in", 1)
# non existing port
ws = WorkflowState(pg)
assert_raises(KeyError, lambda: ws.get(10))
# lonely input port without data
ws = WorkflowState(pg)
assert_raises(KeyError, lambda: ws.get(1))
# lonely input port with data
ws.store_param(1, "param", 0)
assert ws.get(1) == "param"
# connected input port
pg.connect(0, 1)
ws = WorkflowState(pg)
ws.store(0, "data")
assert ws.get(1) == "data"
def test_portgraph_connected_edges():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
vid3 = pg.add_vertex()
assert_raises(InvalidPort, lambda: tuple(pg.connected_edges(0)))
pid1 = pg.add_in_port(vid1, 0)
pid2 = pg.add_in_port(vid1, 1)
pid3 = pg.add_out_port(vid2, 0)
pid4 = pg.add_out_port(vid3, 0)
# test vertices and ports are created without connections
for pid in (pid1, pid2, pid3, pid4):
assert len(tuple(pg.connected_edges(pid))) == 0
eid1 = pg.connect(pid3, pid1)
assert tuple(pg.connected_edges(pid3)) == (eid1,)
assert tuple(pg.connected_edges(pid1)) == (eid1,)
for pid in (pid2, pid4):
assert len(tuple(pg.connected_edges(pid))) == 0
eid2 = pg.connect(pid4, pid1)
assert tuple(pg.connected_edges(pid3)) == (eid1,)
assert tuple(pg.connected_edges(pid4)) == (eid2,)
assert sorted(pg.connected_edges(pid1)) == sorted((eid1, eid2))
assert len(tuple(pg.connected_edges(pid2))) == 0
eid3 = pg.connect(pid4, pid2)
assert tuple(pg.connected_edges(pid3)) == (eid1,)
assert sorted(pg.connected_edges(pid4)) == sorted((eid2, eid3))
assert sorted(pg.connected_edges(pid1)) == sorted((eid1, eid2))
assert tuple(pg.connected_edges(pid2)) == (eid3,)
def test_portgraph_connected_edges():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
vid3 = pg.add_vertex()
assert_raises(InvalidPort, lambda: tuple(pg.connected_edges(0)))
pid1 = pg.add_in_port(vid1, 0)
pid2 = pg.add_in_port(vid1, 1)
pid3 = pg.add_out_port(vid2, 0)
pid4 = pg.add_out_port(vid3, 0)
# test vertices and ports are created without connections
for pid in (pid1, pid2, pid3, pid4):
assert len(tuple(pg.connected_edges(pid))) == 0
eid1 = pg.connect(pid3, pid1)
assert tuple(pg.connected_edges(pid3)) == (eid1,)
assert tuple(pg.connected_edges(pid1)) == (eid1,)
for pid in (pid2, pid4):
assert len(tuple(pg.connected_edges(pid))) == 0
eid2 = pg.connect(pid4, pid1)
assert tuple(pg.connected_edges(pid3)) == (eid1,)
assert tuple(pg.connected_edges(pid4)) == (eid2,)
assert sorted(pg.connected_edges(pid1)) == sorted((eid1, eid2))
assert len(tuple(pg.connected_edges(pid2))) == 0
eid3 = pg.connect(pid4, pid2)
assert tuple(pg.connected_edges(pid3)) == (eid1,)
assert sorted(pg.connected_edges(pid4)) == sorted((eid2, eid3))
assert sorted(pg.connected_edges(pid1)) == sorted((eid1, eid2))
assert tuple(pg.connected_edges(pid2)) == (eid3,)
def test_evaluation_propagated_upstream():
visited = []
def func(txt):
visited.append(txt)
return txt
pg = PortGraph()
n = FuncNode(func)
pg.add_actor(n, 0)
pg.add_actor(n, 1)
pg.connect(pg.out_port(0, 'txt'), pg.in_port(1, 'txt'))
algo = BruteEvaluation(pg)
ws = WorkflowState(pg)
env = EvaluationEnvironment()
ws.store_param(pg.in_port(0, 'txt'), "txt", 0)
algo.eval(env, ws, 0)
assert len(visited) == 1
algo.eval(env, ws, 1)
assert len(visited) == 2
env.new_execution()
algo.eval(env, ws, 1)
assert len(visited) == 4
def test_ws_store_param_only_on_lonely_input_ports():
pg = PortGraph()
pg.add_vertex(0)
pg.add_in_port(0, "in", 0)
pg.add_out_port(0, "out", 1)
pg.add_vertex(1)
pg.add_in_port(1, "in", 2)
pg.connect(1, 2)
ws = WorkflowState(pg)
assert_raises(UserWarning, lambda: ws.store_param(1, "param", 0))
assert_raises(UserWarning, lambda: ws.store_param(2, "param", 0))
def test_ws_sub_ready_for_evaluation_if_no_input_port():
pg = PortGraph()
pg.add_vertex(0)
pg.add_out_port(0, "out", 0)
pg.add_vertex(1)
pg.add_in_port(1, "in", 1)
pg.connect(0, 1)
ws = WorkflowState(pg)
assert ws.is_ready_for_evaluation()
subpg = get_upstream_subportgraph(pg, 1)
subws = WorkflowState(subpg)
assert subws.is_ready_for_evaluation()
def test_portgraph_clear():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
pid1 = pg.add_in_port(vid1, "in")
pid2 = pg.add_out_port(vid2, "out")
pg.connect(pid2, pid1)
pg.clear()
assert pg.nb_vertices() == 0
assert pg.nb_edges() == 0
assert len(tuple(pg.ports())) == 0
def test_portgraph_clear():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
pid1 = pg.add_in_port(vid1, "in")
pid2 = pg.add_out_port(vid2, "out")
pg.connect(pid2, pid1)
pg.clear()
assert pg.nb_vertices() == 0
assert pg.nb_edges() == 0
assert len(tuple(pg.ports())) == 0
def test_ws_retrieve_data_on_multiple_connections_input_ports():
pg = PortGraph()
pg.add_vertex(0)
pg.add_out_port(0, "out", 0)
pg.add_vertex(1)
pg.add_out_port(1, "out", 1)
pg.add_vertex(2)
pg.add_in_port(2, "in", 2)
pg.connect(0, 2)
pg.connect(1, 2)
ws = WorkflowState(pg)
assert_raises(KeyError, lambda: ws.get(2))
ws.store(0, "data0")
assert_raises(KeyError, lambda: ws.get(2))
ws.store(1, "data1")
assert tuple(ws.get(2)) == ("data0", "data1")
def test_portgraph_remove_port():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
pid1 = pg.add_in_port(vid1, "in")
pid2 = pg.add_out_port(vid2, "out")
pg.connect(pid2, pid1)
# raise error if global port id dos not exist
assert_raises(InvalidPort, lambda: pg.remove_port(pid1 + pid2 + 1))
pg.remove_port(pid1)
assert len(tuple(pg.ports(vid1))) == 0
assert tuple(pg.ports(vid2)) == (pid2,)
assert pg.nb_connections(pid2) == 0
def test_portgraph_remove_port():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
pid1 = pg.add_in_port(vid1, "in")
pid2 = pg.add_out_port(vid2, "out")
pg.connect(pid2, pid1)
# raise error if global port id dos not exist
assert_raises(InvalidPort, lambda: pg.remove_port(pid1 + pid2 + 1))
pg.remove_port(pid1)
assert len(tuple(pg.ports(vid1))) == 0
assert tuple(pg.ports(vid2)) == (pid2,)
assert pg.nb_connections(pid2) == 0
def test_portgraph_remove_vertex():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
pid1 = pg.add_in_port(vid1, "in")
pid2 = pg.add_out_port(vid2, "out")
pg.connect(pid2, pid1)
assert_raises(InvalidVertex, lambda: pg.remove_vertex(vid1 + vid2 + 1))
pg.remove_vertex(vid1)
assert tuple(pg.ports()) == (pid2,)
assert_raises(InvalidVertex, lambda: pg.ports(vid1).next())
assert tuple(pg.ports(vid2)) == (pid2,)
assert pg.nb_connections(pid2) == 0
assert pg.nb_neighbors(vid2) == 0
def test_portgraph_remove_vertex():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
pid1 = pg.add_in_port(vid1, "in")
pid2 = pg.add_out_port(vid2, "out")
pg.connect(pid2, pid1)
assert_raises(InvalidVertex, lambda: pg.remove_vertex(vid1 + vid2 + 1))
pg.remove_vertex(vid1)
assert tuple(pg.ports()) == (pid2,)
assert_raises(InvalidVertex, lambda: pg.ports(vid1).next())
assert tuple(pg.ports(vid2)) == (pid2,)
assert pg.nb_connections(pid2) == 0
assert pg.nb_neighbors(vid2) == 0
def test_ws_is_ready_for_evaluation():
pg = PortGraph()
pg.add_vertex(0)
pg.add_in_port(0, "in", 0)
pg.add_out_port(0, "out", 1)
pg.add_vertex(1)
pg.add_out_port(1, "out", 2)
pg.add_vertex(2)
pg.add_in_port(2, "in", 3)
pg.add_out_port(2, "out", 4)
pg.connect(1, 3)
pg.connect(2, 3)
ws = WorkflowState(pg)
assert not ws.is_ready_for_evaluation()
ws.store(1, "data")
assert not ws.is_ready_for_evaluation()
ws.store_param(0, "param", 0)
assert ws.is_ready_for_evaluation()
def test_portgraph_connect():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
# invalid ports
assert_raises(InvalidPort, lambda: pg.connect(0, 1))
# invalid source port
pid1 = pg.add_in_port(vid1, "in")
assert_raises(InvalidPort, lambda: pg.connect(pid1 + 1, pid1))
# invalid out port
pid2 = pg.add_out_port(vid2, "out")
assert_raises(InvalidPort, lambda: pg.connect(pid2, pid1 + pid2 + 1))
# edge connection from in to out raise error
assert_raises(InvalidPort, lambda: pg.connect(pid1, pid2))
eid = pg.connect(pid2, pid1)
assert pg.source_port(eid) == pid2
assert pg.target_port(eid) == pid1
assert tuple(pg.connected_edges(pid1)) == (eid,)
assert tuple(pg.connected_edges(pid2)) == (eid,)
assert pid1 in pg.connected_ports(pid2)
assert pid2 in pg.connected_ports(pid1)
# can not duplicate edge
assert_raises(InvalidEdge, lambda: pg.connect(pid2, pid1, eid))
def portgraph_nb_connections():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
vid3 = pg.add_vertex()
assert_raises(InvalidPort, lambda: pg.nb_connections(0))
pid1 = pg.add_in_port(vid1, 0)
pid2 = pg.add_in_port(vid1, 1)
pid3 = pg.add_out_port(vid2, 0)
pid4 = pg.add_out_port(vid3, 0)
for pid in (pid1, pid2, pid3, pid4):
assert pg.nb_connections(pid) == 0
pg.connect(pid3, pid1)
assert pg.nb_connections(pid3) == 1
assert pg.nb_connections(pid1) == 1
assert pg.nb_connections(pid2) == 0
assert pg.nb_connections(pid4) == 0
pg.connect(pid4, pid1)
assert pg.nb_connections(pid3) == 1
assert pg.nb_connections(pid4) == 1
assert pg.nb_connections(pid1) == 2
assert pg.nb_connections(pid2) == 0
pg.connect(pid4, pid2)
assert pg.nb_connections(pid3) == 1
assert pg.nb_connections(pid4) == 2
assert pg.nb_connections(pid1) == 2
assert pg.nb_connections(pid2) == 1
def test_portgraph_connected_ports():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
vid3 = pg.add_vertex()
assert_raises(InvalidPort, lambda: tuple(pg.connected_ports(0)))
pid1 = pg.add_in_port(vid1, 0)
pid2 = pg.add_in_port(vid1, 1)
pid3 = pg.add_out_port(vid2, 0)
pid4 = pg.add_out_port(vid3, 0)
for pid in (pid1, pid2, pid3, pid4):
assert len(tuple(pg.connected_ports(pid))) == 0
pg.connect(pid3, pid1)
assert tuple(pg.connected_ports(pid3)) == (pid1,)
assert tuple(pg.connected_ports(pid1)) == (pid3,)
for pid in (pid2, pid4):
assert len(tuple(pg.connected_ports(pid))) == 0
pg.connect(pid4, pid1)
assert tuple(pg.connected_ports(pid3)) == (pid1,)
assert tuple(pg.connected_ports(pid4)) == (pid1,)
assert sorted(pg.connected_ports(pid1)) == sorted((pid3, pid4))
assert len(tuple(pg.connected_ports(pid2))) == 0
pg.connect(pid4, pid2)
assert tuple(pg.connected_ports(pid3)) == (pid1,)
assert sorted(pg.connected_ports(pid4)) == sorted((pid1, pid2))
assert sorted(pg.connected_ports(pid1)) == sorted((pid3, pid4))
assert tuple(pg.connected_ports(pid2)) == (pid4,)
def test_portgraph_connected_ports():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
vid3 = pg.add_vertex()
assert_raises(InvalidPort, lambda: tuple(pg.connected_ports(0)))
pid1 = pg.add_in_port(vid1, 0)
pid2 = pg.add_in_port(vid1, 1)
pid3 = pg.add_out_port(vid2, 0)
pid4 = pg.add_out_port(vid3, 0)
for pid in (pid1, pid2, pid3, pid4):
assert len(tuple(pg.connected_ports(pid))) == 0
pg.connect(pid3, pid1)
assert tuple(pg.connected_ports(pid3)) == (pid1,)
assert tuple(pg.connected_ports(pid1)) == (pid3,)
for pid in (pid2, pid4):
assert len(tuple(pg.connected_ports(pid))) == 0
pg.connect(pid4, pid1)
assert tuple(pg.connected_ports(pid3)) == (pid1,)
assert tuple(pg.connected_ports(pid4)) == (pid1,)
assert sorted(pg.connected_ports(pid1)) == sorted((pid3, pid4))
assert len(tuple(pg.connected_ports(pid2))) == 0
pg.connect(pid4, pid2)
assert tuple(pg.connected_ports(pid3)) == (pid1,)
assert sorted(pg.connected_ports(pid4)) == sorted((pid1, pid2))
assert sorted(pg.connected_ports(pid1)) == sorted((pid3, pid4))
assert tuple(pg.connected_ports(pid2)) == (pid4,)
def portgraph_nb_connections():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
vid3 = pg.add_vertex()
assert_raises(InvalidPort, lambda: pg.nb_connections(0))
pid1 = pg.add_in_port(vid1, 0)
pid2 = pg.add_in_port(vid1, 1)
pid3 = pg.add_out_port(vid2, 0)
pid4 = pg.add_out_port(vid3, 0)
for pid in (pid1, pid2, pid3, pid4):
assert pg.nb_connections(pid) == 0
pg.connect(pid3, pid1)
assert pg.nb_connections(pid3) == 1
assert pg.nb_connections(pid1) == 1
assert pg.nb_connections(pid2) == 0
assert pg.nb_connections(pid4) == 0
pg.connect(pid4, pid1)
assert pg.nb_connections(pid3) == 1
assert pg.nb_connections(pid4) == 1
assert pg.nb_connections(pid1) == 2
assert pg.nb_connections(pid2) == 0
pg.connect(pid4, pid2)
assert pg.nb_connections(pid3) == 1
assert pg.nb_connections(pid4) == 2
assert pg.nb_connections(pid1) == 2
assert pg.nb_connections(pid2) == 1
def test_portgraph_connect():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
# invalid ports
assert_raises(InvalidPort, lambda: pg.connect(0, 1))
# invalid source port
pid1 = pg.add_in_port(vid1, "in")
assert_raises(InvalidPort, lambda: pg.connect(pid1 + 1, pid1))
# invalid out port
pid2 = pg.add_out_port(vid2, "out")
assert_raises(InvalidPort, lambda: pg.connect(pid2, pid1 + pid2 + 1))
# edge connection from in to out raise error
assert_raises(InvalidPort, lambda: pg.connect(pid1, pid2))
eid = pg.connect(pid2, pid1)
assert pg.source_port(eid) == pid2
assert pg.target_port(eid) == pid1
assert tuple(pg.connected_edges(pid1)) == (eid,)
assert tuple(pg.connected_edges(pid2)) == (eid,)
assert pid1 in pg.connected_ports(pid2)
assert pid2 in pg.connected_ports(pid1)
# can not duplicate edge
assert_raises(InvalidEdge, lambda: pg.connect(pid2, pid1, eid))
def test_portgraph_edge_connected_to_ports():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
# method add_edge is forbidden
assert_raises(UserWarning, lambda: pg.add_edge((vid1, vid2)))
# connect to None port raises InvalidPort
assert_raises(InvalidPort, lambda: pg.connect(None, None))
pid1 = pg.add_out_port(vid1, "out")
pid2 = pg.add_in_port(vid2, "in")
assert_raises(InvalidPort, lambda: pg.connect(pid1, None))
assert_raises(InvalidPort, lambda: pg.connect(None, pid2))
# connect from in port to out port raises InvalidPort
assert_raises(InvalidPort, lambda: pg.connect(pid2, pid1))
# test connect is working
eid = pg.connect(pid1, pid2)
assert pg.source_port(eid) == pid1
assert pg.target_port(eid) == pid2
def test_portgraph_edge_connected_to_ports():
pg = PortGraph()
vid1 = pg.add_vertex()
vid2 = pg.add_vertex()
# method add_edge is forbidden
assert_raises(UserWarning, lambda: pg.add_edge((vid1, vid2)))
# connect to None port raises InvalidPort
assert_raises(InvalidPort, lambda: pg.connect(None, None))
pid1 = pg.add_out_port(vid1, "out")
pid2 = pg.add_in_port(vid2, "in")
assert_raises(InvalidPort, lambda: pg.connect(pid1, None))
assert_raises(InvalidPort, lambda: pg.connect(None, pid2))
# connect from in port to out port raises InvalidPort
assert_raises(InvalidPort, lambda: pg.connect(pid2, pid1))
# test connect is working
eid = pg.connect(pid1, pid2)
assert pg.source_port(eid) == pid1
assert pg.target_port(eid) == pid2
def test_ws_when_connected_input_port():
pg = PortGraph()
pg.add_vertex(0)
pg.add_out_port(0, "out", 0)
pg.add_vertex(1)
pg.add_out_port(1, "out", 1)
pg.add_vertex(2)
pg.add_in_port(2, "in", 2)
pg.connect(0, 2)
ws = WorkflowState(pg)
assert ws.when(2) is None
ws.set_last_evaluation(0, 10)
assert ws.when(2) == 10
pg.connect(1, 2)
ws = WorkflowState(pg)
assert ws.when(2) is None
ws.set_last_evaluation(0, 10)
assert ws.when(2) is None
ws.set_last_evaluation(1, 11)
assert ws.when(2) == 10
def test_portgraph_big():
pg = PortGraph()
vid1 = pg.add_vertex()
pid11 = pg.add_out_port(vid1, "out")
vid2 = pg.add_vertex()
pid21 = pg.add_out_port(vid2, "out")
vid3 = pg.add_vertex()
pid31 = pg.add_in_port(vid3, "in1")
pid32 = pg.add_in_port(vid3, "in2")
pid33 = pg.add_out_port(vid3, "res")
vid4 = pg.add_vertex()
pid41 = pg.add_in_port(vid4, "in")
eid1 = pg.connect(pid11, pid31)
eid2 = pg.connect(pid21, pid32)
pg.connect(pid33, pid41)
assert pg.source_port(eid1) == pid11
assert pg.target_port(eid2) == pid32
assert set(pg.out_ports(vid1)) == {pid11}
assert set(pg.in_ports(vid3)) == {pid31, pid32}
assert set(pg.ports(vid3)) == {pid31, pid32, pid33}
assert pg.is_in_port(pid31)
assert pg.is_out_port(pid11)
assert pg.vertex(pid11) == vid1
assert set(pg.connected_ports(pid11)) == {pid31}
assert set(pg.connected_edges(pid21)) == {eid2}
assert pg.out_port(vid1, "out") == pid11
assert pg.in_port(vid3, "in1") == pid31
assert_raises(InvalidPort, lambda: pg.connect(pid11, pid33))
pg.remove_port(pid33)
assert set(pg.connected_ports(pid41)) == set()
assert set(pg.out_edges(vid3)) == set()
assert_raises(InvalidPort, lambda: pg.is_in_port(pid33))
def test_portgraph_big():
pg = PortGraph()
vid1 = pg.add_vertex()
pid11 = pg.add_out_port(vid1, "out")
vid2 = pg.add_vertex()
pid21 = pg.add_out_port(vid2, "out")
vid3 = pg.add_vertex()
pid31 = pg.add_in_port(vid3, "in1")
pid32 = pg.add_in_port(vid3, "in2")
pid33 = pg.add_out_port(vid3, "res")
vid4 = pg.add_vertex()
pid41 = pg.add_in_port(vid4, "in")
eid1 = pg.connect(pid11, pid31)
eid2 = pg.connect(pid21, pid32)
pg.connect(pid33, pid41)
assert pg.source_port(eid1) == pid11
assert pg.target_port(eid2) == pid32
assert set(pg.out_ports(vid1)) == {pid11}
assert set(pg.in_ports(vid3)) == {pid31, pid32}
assert set(pg.ports(vid3)) == {pid31, pid32, pid33}
assert pg.is_in_port(pid31)
assert pg.is_out_port(pid11)
assert pg.vertex(pid11) == vid1
assert set(pg.connected_ports(pid11)) == {pid31}
assert set(pg.connected_edges(pid21)) == {eid2}
assert pg.out_port(vid1, "out") == pid11
assert pg.in_port(vid3, "in1") == pid31
assert_raises(InvalidPort, lambda: pg.connect(pid11, pid33))
pg.remove_port(pid33)
assert set(pg.connected_ports(pid41)) == set()
assert set(pg.out_edges(vid3)) == set()
assert_raises(InvalidPort, lambda: pg.is_in_port(pid33))
def test_ws_dos_not_allow_graph_editing():
pg = PortGraph()
ws = WorkflowState(pg)
assert ws.portgraph_still_valid()
pg.add_vertex(0)
assert not ws.portgraph_still_valid()
ws = WorkflowState(pg)
assert ws.portgraph_still_valid()
pg.add_out_port(0, "out", 0)
assert not ws.portgraph_still_valid()
pg.add_vertex(1)
pg.add_in_port(1, "in", 1)
ws = WorkflowState(pg)
assert ws.portgraph_still_valid()
pg.connect(0, 1)
assert not ws.portgraph_still_valid()
ws = WorkflowState(pg)
assert ws.portgraph_still_valid()
pg.remove_port(0)
assert not ws.portgraph_still_valid()
def get_pg():
pg = PortGraph()
pg.add_vertex(0)
pg.add_out_port(0, "out", 0)
pg.add_vertex(1)
pg.add_out_port(1, "out", 1)
pg.add_vertex(2)
pg.add_in_port(2, "in1", 2)
pg.add_in_port(2, "in2", 3)
pg.add_out_port(2, "res", 4)
pg.add_vertex(3)
pg.add_in_port(3, "in", 5)
pg.add_vertex(4)
pg.add_out_port(4, "out", 6)
pg.connect(0, 2, 0)
pg.connect(1, 3, 1)
pg.connect(4, 5, 2)
pg.connect(6, 3, 3)
return pg
def get_pg():
pg = PortGraph()
pg.add_vertex(0)
pg.add_out_port(0, "out", 0)
pg.add_vertex(1)
pg.add_out_port(1, "out", 1)
pg.add_vertex(2)
pg.add_in_port(2, "in1", 2)
pg.add_in_port(2, "in2", 3)
pg.add_out_port(2, "res", 4)
pg.add_vertex(3)
pg.add_in_port(3, "in", 5)
pg.add_vertex(4)
pg.add_out_port(4, "out", 6)
pg.connect(0, 2, 0)
pg.connect(1, 3, 1)
pg.connect(4, 5, 2)
pg.connect(6, 3, 3)
return pg
