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    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "config": {
        "view": {
            "stroke": null
        }
    },
    "description": "Rules (line segments) connecting SEA to every airport reachable via direct flight",
    "height": 500,
    "layer": [
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            },
            "encoding": {
                "color": {
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            "encoding": {
                "color": {
                    "value": "gray"
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                "latitude": {
                    "field": "latitude",
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                "longitude": {
                    "field": "longitude",
                    "type": "quantitative"
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                "size": {
                    "value": 5
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            "mark": "circle"
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                "longitude2": {
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                    "filter": {
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                        "field": "origin"
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                    "from": {
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}