apollo-common/src/main/java/com/ctrip/framework/apollo/common/dto/PageDTO.java/PageDTO/PageDTO
class PageDTO:  public PageDTO(List<T> content, Pageable pageable, long total) {
    this.total = total;
    this.content = content;
    this.page = pageable.getPageNumber();
    this.size = pageable.getPageSize();
  }