Registering custom decorators

I have a custom decorator for pagination using query strings but I have not been able to get Swagger to pick them up

// pagination.decorator.ts
import {createRouteParamDecorator} from '@nestjs/common';
import config from 'config';
import {Request} from 'express';
import {PaginationOptions} from './pagination.model';

export const Pagination: Function = createRouteParamDecorator(
  (_: string, req: Request): PaginationOptions => {
    req.query.limit = (typeof req.query.limit === 'number') ?
      req.query.limit :
      parseInt(req.query.limit, 10) || config.pagination.size;

    req.query.page = (typeof req.query.page === 'number') ?
      req.query.page :
      parseInt(req.query.page, 10) || 1;

    if (req.query.limit > config.pagination.max) {
      req.query.limit = config.pagination.max;
    } else if (req.query.limit < config.pagination.min) {
      req.query.limit = config.pagination.min;
    }

    const limit: number = req.query.limit;
    const page: number = req.query.page;

    return {
      limit,
      page
    };
  }
);

// pagination.model.ts
import {ApiModelPropertyOptional} from '@nestjs/swagger';

export class PaginationOptions {
  @ApiModelPropertyOptional() public readonly limit: number;
  @ApiModelPropertyOptional() public readonly page: number;
}

// documents.controller.ts
....
  @Get()
  @ApiResponse(swagger.NOCONTENT)
  @ApiResponse(swaggerWithType(swagger.OK, Document))
  public async httpGetAll (
    @Pagination() pagination: PaginationOptions
  ): Promise<PaginateResult<Role>> {
    return this.documentService.readAll(pagination);
  }
....

Start with pagination.decorator.ts and documents.controller.ts, then inspect how the Swagger module processes the @Pagination() parameter and the PaginationOptions model in pagination.model.ts. Confirm the desired result by checking generated Swagger output: the pagination query parameters should be represented for the endpoint.