Add subplots anchor test

Author: dy

test/image/mocks/gl2d_subplots_anchor.json

@@ -0,0 +1,39 @@
+{
+    "data": [
+    {
+      "x": ["2007-01-03", "2007-01-04", "2007-01-05", "2007-01-08", "2007-01-09", "2007-01-10", "2007-01-11", "2007-01-12", "2007-01-16", "2007-01-17", "2007-01-18", "2007-01-19", "2007-01-22", "2007-01-23", "2007-01-24"],
+      "y": [309579900, 211815100, 208685400, 199276700, 837324600, 738220000, 360063200, 328172600, 311019100, 411565000, 591151400, 341118400, 363506500, 301856100, 231953400],
+      "mode": "lines",
+      "name": "volume",
+      "type": "scattergl",
+      "xaxis": "x",
+      "yaxis": "y"
+    },
+    {
+      "x": ["2007-01-03", "2007-01-04", "2007-01-05", "2007-01-08", "2007-01-09", "2007-01-10", "2007-01-11", "2007-01-12", "2007-01-16", "2007-01-17", "2007-01-18", "2007-01-19", "2007-01-22", "2007-01-23", "2007-01-24"],
+      "y": [10.812461, 11.05245, 10.973744, 11.027936, 11.944027, 12.515616, 12.360785, 12.208533, 12.528519, 12.251111, 11.492433, 11.418888, 11.198251, 11.057612, 11.186639],
+      "mode": "lines",
+      "name": "adjusted",
+      "type": "scattergl",
+      "xaxis": "x",
+      "yaxis": "y2"
+    }
+  ],
+  "layout": {
+    "width": 700,
+    "height": 400,
+    "showlegend": false,
+    "xaxis": {
+      "domain": [0, 1],
+      "anchor": "y2"
+    },
+    "yaxis2": {
+      "domain": [0, 0.45],
+      "anchor": "x"
+    },
+    "yaxis": {
+      "domain": [0.55, 1],
+      "anchor": "x"
+    }
+  }
+}