anchor.diff:      };
       var csObs = new CaseSelectObserver();
       
  -    function nrKeys(a) {
  +    function nrKeysAssociativeArrays(a) {
           var i = 0;
           for (var key in a) i++;
           return i;
  
positive.code:         var histCaseIdMap = {};
          var rows = dt.getNumberOfRows();
          var t = dt.getColumnType(col);
          if (t=="number") {
              if (bins==null) bins = 10;
              if ((typeof bins)==(typeof 1)) {
  
negative.code:             var count = {};
              for (var r=0; r<rows; r++) {
                  var caseId = dt.getValue(r,0);
                  if (filter && !caseIdsFilter[caseId]) continue;
                  var v = dt.getValue(r,col);
                  if (v==null) continue;
                  if(count[v]==null) count[v] = [];
  