docs: @Override
      protected HashMap readFile(HashMap brMap) throws IOException {
  
          HashMap ret = new HashMap();
          ArrayList<HashMap> expArr = new ArrayList<HashMap>();
          HashMap<String, HashMap> files = readObvData(brMap);
  //        compressData(file);
          ArrayList<HashMap> obvData;
          HashMap obv;
          HashMap expData;
  
          for (String exname : files.keySet()) {
              obvData = (ArrayList) files.get(exname).get(obvDataKey);
              for (HashMap obvSub : obvData) {
                  expData = new HashMap();
                  obv = new HashMap();
                  copyItem(expData, files.get(exname), "exname");
                  copyItem(expData, files.get(exname), "crid");
                  copyItem(expData, files.get(exname), "local_name");
                  expData.put(jsonKey, obv);
                  obv.put(obvFileKey, obvSub.get(obvDataKey));
                  expArr.add(expData);
              }
          }
  
          // remove index variables
          ArrayList idNames = new ArrayList();
          idNames.add("trno_t");
          removeIndex(expArr, idNames);
          ret.put("experiments", expArr);
  
          return ret;
      }