{
  "function": "viewerUpdate",
  "cases": [
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    {"name":"next-at-the-last-frame-stays","args":[{"index":10,"last":10,"playing":false},{"tag":"Next"}],"expected":{"index":10,"last":10,"playing":false}},
    {"name":"prev-moves-one-frame-back","args":[{"index":3,"last":10,"playing":false},{"tag":"Prev"}],"expected":{"index":2,"last":10,"playing":false}},
    {"name":"prev-at-the-first-frame-stays","args":[{"index":0,"last":10,"playing":false},{"tag":"Prev"}],"expected":{"index":0,"last":10,"playing":false}},
    {"name":"first-goes-to-frame-zero","args":[{"index":7,"last":10,"playing":false},{"tag":"First"}],"expected":{"index":0,"last":10,"playing":false}},
    {"name":"last-goes-to-the-last-frame","args":[{"index":2,"last":10,"playing":false},{"tag":"Last"}],"expected":{"index":10,"last":10,"playing":false}},
    {"name":"toggle-play-starts-autoplay","args":[{"index":4,"last":10,"playing":false},{"tag":"TogglePlay"}],"expected":{"index":4,"last":10,"playing":true}},
    {"name":"toggle-play-stops-autoplay","args":[{"index":4,"last":10,"playing":true},{"tag":"TogglePlay"}],"expected":{"index":4,"last":10,"playing":false}},
    {"name":"toggle-play-at-the-end-starts-again-from-the-first-frame","args":[{"index":10,"last":10,"playing":false},{"tag":"TogglePlay"}],"expected":{"index":0,"last":10,"playing":true}},
    {"name":"beat-while-playing-moves-one-frame-forward","args":[{"index":4,"last":10,"playing":true},{"tag":"Beat"}],"expected":{"index":5,"last":10,"playing":true}},
    {"name":"beat-while-not-playing-is-ignored","args":[{"index":4,"last":10,"playing":false},{"tag":"Beat"}],"expected":{"index":4,"last":10,"playing":false}},
    {"name":"beat-that-reaches-the-last-frame-stops-autoplay","args":[{"index":9,"last":10,"playing":true},{"tag":"Beat"}],"expected":{"index":10,"last":10,"playing":false}},
    {"name":"next-while-playing-keeps-playing","args":[{"index":4,"last":10,"playing":true},{"tag":"Next"}],"expected":{"index":5,"last":10,"playing":true}},
    {"name":"prev-while-playing-keeps-playing","args":[{"index":4,"last":10,"playing":true},{"tag":"Prev"}],"expected":{"index":3,"last":10,"playing":true}},
    {"name":"last-while-playing-stops-autoplay","args":[{"index":4,"last":10,"playing":true},{"tag":"Last"}],"expected":{"index":10,"last":10,"playing":false}},
    {"name":"first-while-playing-keeps-playing","args":[{"index":4,"last":10,"playing":true},{"tag":"First"}],"expected":{"index":0,"last":10,"playing":true}},
    {"name":"a-recording-with-no-actions-cannot-play","args":[{"index":0,"last":0,"playing":false},{"tag":"TogglePlay"}],"expected":{"index":0,"last":0,"playing":false}},
    {"name":"a-recording-with-no-actions-stays-at-frame-zero","args":[{"index":0,"last":0,"playing":false},{"tag":"Next"}],"expected":{"index":0,"last":0,"playing":false}}
  ]
}