code: private ArrayList<HashMap> getDataList(Map expData, String blockName, String dataListName) {
          HashMap dataBlock = getObjectOr(expData, blockName, new HashMap());
          return getObjectOr(dataBlock, dataListName, new ArrayList<HashMap>());
      }
docs: Get sub data array from experiment data object
  
  @param expData experiment data holder
  @param blockName top level block name
  @param dataListName sub array name
  @return sub data array