apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/component/txtresolver/PropertyResolver.java/PropertyResolver/handleBlankLine
class PropertyResolver:  private void handleBlankLine(Long namespaceId, ItemDTO oldItem, int lineCounter, ItemChangeSets changeSets) {
    if (!isBlankItem(oldItem)) {
      changeSets.addCreateItem(buildBlankItem(0L, namespaceId, lineCounter));
    }
  }