digraph {
    node [shape = "box", style = "filled, rounded"]

    subgraph clusterorigin {
        label = "origin"

        node [color = orchid]

        omaster[label = "master"]
    }

    subgraph clusterlocal {
        label = "local"

        node [color = orchid]

        master[label = "master"]
    }

    subgraph clusterupstream {
        label = "upstream"

        node [color = limegreen]

        umaster[label = "master"]
    }

    omaster -> master [label = "git pull"]
    master -> omaster [label = "git push", constraint = false]
    umaster -> master [label = "git pull upstream master", constraint = false]
    omaster -> umaster [label = "pull request (GitHub)\nmerge request (GitLab)", constraint = false]
}