code: @Override
    public Object get(String attributeName) {
      if (cachedValueMap == null) {
        cachedValueMap = new LinkedHashMap<>();
      }
  
      Object value;
      if (cachedValueMap.containsKey(attributeName)) {
        value = cachedValueMap.get(attributeName);
      } else {
        Integer col = colNamesMap.get(attributeName);
        if (col != null) {
          Cell cell = row.getCell(col);
          if (cell != null) {
            value = ExcelUtils.toValue(cell, cellProcessors);
          } else {
            value = null;
          }
        } else {
          value = null;
        }
  
        cachedValueMap.put(attributeName, value);
      }
      return value;
    }
docs: Gets an Attribute (Cell value).
  
  <p>All values are retrieved as String, returns null if the attributeName is unknown