mojtaba-proof multicategory sorting mock

Author: etpinard

test/image/baselines/multicategory-sorting.png

@@ -26,6 +26,21 @@
         "y":  [1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6],
         "xaxis": "x3",
         "yaxis": "y3"
+    },
+
+    {
+        "x": [[1, 2, 3, 4, 5, 6],
+              [1, 2, 1, 2, null, 2]],
+        "y":  [1, 2, 3, 4, 5, 6],
+        "xaxis": "x4",
+        "yaxis": "y4"
+    },
+    {
+        "x": [[4, 5, 6, 7, 8, 9],
+              [1, null, 1, 2, 1, 2]],
+        "y":  [1, 2, 3, 4, 5, 6],
+        "xaxis": "x4",
+        "yaxis": "y4"
     }],
     "layout": {
         "grid": {"rows": 2, "columns": 2, "pattern": "independent", "xgap": 0.1, "ygap": 0.15},