adding back the CeNDR track custom coloring

config.json

@@ -10867,7 +10867,11 @@
          "displays" : [
             {
                "type" : "LinearVariantDisplay",
-               "displayId" : "cendr_variation-c_elegans_PRJNA13758-LinearVariantDisplay"
+               "displayId" : "cendr_variation-c_elegans_PRJNA13758-LinearVariantDisplay",
+               "renderer": {
+                  "type": "SvgFeatureRenderer",
+                  "color1": "jexl:variantColor(feature)"
+                }
             }
          ],
          "description" : "Strain variant data from https://www.elegansvariation.org/.  For more information see Cook DE, Zdraljevic S, Roberts JP, Andersen EC. CeNDR, the Caenorhabditis elegans natural diversity resource. Nucleic Acids Res. 2017 Jan 4;45(D1):D650-D657. doi: 10.1093/nar/gkw893. Epub 2016 Oct 3. PubMed PMID: 27701074; PubMed Central PMCID: PMC5210618. Colors follow the same scheme as ENSEMBL for predicted variants (https://uswest.ensembl.org/info/genome/variation/prediction/predicted_data.html), and variants with no predicted impact are black and variants that don't have recognized predicted consequence are peachpuff (a pale pink-orange). Variants with more than one predicted consequences are colored by the first annotation.",

variantColor_plugin.js

@@ -5,7 +5,7 @@
 
     install(pluginManager) {
       pluginManager.jexl.addFunction('variantColor', f => {
-            if (f['variant']['INFO']['ANN']) {
+            if ('variant' in f && 'INFO' in f['variant'] && 'ANN' in f['variant']['INFO']) {
                 var ann = f['variant']['INFO']['ANN'][0].split('|')
                 var cons = ann[1]
                 if (cons.indexOf('&') > -1) {