docs: @XmlElement(name = "pageRequest", required = true)
      @JsonProperty(value = "pageRequest", required = true)
      @ApiModelProperty(value = "The page request.", position = 1, required = true)
      @Override
      public PageRequestDto getPageRequest() {
          if (this.pageRequest == null) {
              this.pageRequest = new PageRequestDto();
          }
          return pageRequest;
      }