def METHOD_NAME(self) -> Graph:
    """Return a graph with a well-known contents."""
    graph = Graph()
    graph.add_node(_create_simple_node("input", []))
    graph.add_node(_create_simple_node("a:b", ["a"]))
    graph.add_node(_create_simple_node("a:b:c1", ["a", "a:b"]))
    graph.add_node(_create_simple_node("a:b:c2", ["a", "a:b"]))
    graph.add_node(_create_simple_node("a:b:c:d", ["a", "a:b", "a:b:c"]))
    graph.add_node(_create_simple_node("e", ["e"]))
    graph.add_node(_create_simple_node("output", []))
    graph.add_edge("input", "a:b")
    graph.add_edge("a:b", "a:b:c1")
    graph.add_edge("a:b", "a:b:c2")
    graph.add_edge("a:b:c1", "a:b:c:d")
    graph.add_edge("a:b:c2", "a:b:c:d")
    graph.add_edge("a:b:c:d", "output")
    graph.add_edge("input", "e")
    graph.add_edge("e", "output")
    return graph