digraph G {
    rankdir=LR
    labeljust=l
    fontsize=20
    
    subgraph faucet {
        color=lightgrey;
        subgraph cluster_faucet {
            label="Faucet"
            faucet_pull [label="pull: file/stdin"]
            faucet_push [label=push]
            style="rounded"
        }
        fauct_exit_pull [shape=plaintext, label=""]
        faucet_pull -> faucet_push
        faucet_push -> fauct_exit_pull [style=dashed]
    }
    

    subgraph drain {
        color=lightgrey;
        drain_input [shape=plaintext, label=""]
        drain_input -> drain_pull [style="dashed"]
        subgraph cluster_drain {
            label = "Drain"
            drain_pull [label=pull]
            drain_push [label="push: file/stdout"]
            style="rounded"
        }
        drain_pull -> drain_push
    }

    subgraph launch {
        color=lightgrey;
        subgraph cluster_launch {
            label="Launch"
            launch_pull [label=pull]
            launch_stdin_recv_push [label=push]
            
            subgraph cluster_spawn_holder {
                color=white
                label=""
                subgraph cluster_launch_spawn {
                    color=grey
                    label="child.spawn"
                    launch_stdin_recv_pull [label="pull:stdin"]
                    launch_stdout_send_pull [label="pull:stdout"]
                    launch_stderr_send_pull [label="pull:stdout"]
                    style="filled"
                }
                launch_exit_send_push [label="push:exit"]
            }
            launch_stderr_recv_push [label="push"]
            launch_stdout_recv_push [label="push"]
            style="rounded"
        }
        launch_input [shape=plaintext, label=""]
        launch_input -> launch_pull [style="dashed"]
        launch_pull -> launch_stdin_recv_push
        launch_stdin_recv_push -> launch_stdin_recv_pull [style=dashed]
        launch_stdin_recv_pull -> launch_stdout_send_pull [style=dotted, arrowhead=none]
        launch_stdin_recv_pull -> launch_stderr_send_pull [style=dotted, arrowhead=none]
        
        launch_stdout_send_pull -> launch_stdout_recv_push
        launch_stderr_send_pull -> launch_stderr_recv_push
        launch_stdout_recv_push -> launch_stdout_outer [style=dashed]
        launch_stderr_recv_push -> launch_stderr_outer [style=dashed]
        launch_exit_send_push -> launch_exit_outer [style=dashed]
        subgraph cluster_launch_outputs {
            color=white
            launch_stderr_outer [shape=plaintext, label=""]
            launch_stdout_outer [shape=plaintext, label=""]
            launch_exit_outer [shape=plaintext, label=""]
        }
    }


    subgraph buffer {
        color=lightgrey;
        buffer_input_push [shape=plaintext, label=""]
        subgraph cluster_buffer {
            label = "Buffer"
            buffer_pull [label=pull]
            buffer_push [label=push]
            buffer_push -> buffer_inner_pull [style=dashed, arrowhead=empty]
            buffer_inner_pull [label=pull]
            buffer_inner_push [label=push]
            buffer_inner_pull -> buffer_inner_push
            style="rounded"
        }
        buffer_input_push -> buffer_pull [style=dashed]
        buffer_pull -> buffer_push
        buffer_exit_pull [shape=plaintext, label=""]
        buffer_inner_push -> buffer_exit_pull [style=dashed]
    }


    subgraph junction {
        color=lightgrey;
        subgraph cluster_junction {
            label = "Junction"
            junction_push_1 [label=push]
            junction_push_2 [label=push]
            junction_pull_1 [label=pull]
            junction_pull_2 [label=pull]
            style="rounded"
        }
        junction_input_outer_1 [shape="plaintext", label=""]
        junction_input_outer_2 [shape="plaintext", label=""]
        junction_input_outer_1 -> junction_pull_1 [style=dashed]
        junction_input_outer_2 -> junction_pull_2 [style=dashed]
        junction_pull_1 -> junction_push_1
        junction_pull_2 -> junction_push_1
        junction_pull_1 -> junction_push_2
        junction_pull_2 -> junction_push_2
        junction_exit_pull_1 [shape=plaintext, label=""]
        junction_exit_pull_2 [shape=plaintext, label=""]
        junction_push_1 -> junction_exit_pull_1 [style=dashed]
        junction_push_2 -> junction_exit_pull_2 [style=dashed]
    }



    subgraph cluster_legend {
        label="Legend"
        a [label=""]
        b [label=""]
        c [label=""]
        d [label=""]
        e [label=""]
        f [label=""]
        g [label=""]
        h [label=""]
        a -> b [label=motion]
        c -> d [label=io, style=dotted, arrowhead=none]
        e -> f [label="channel synchronous", style=dashed]
        g -> h [label="channel asynchronous", style=dashed, arrowhead=empty]
    }


}