code: func (c *ECS) ListTaskDefinitionFamiliesPages(input *ListTaskDefinitionFamiliesInput, fn func(*ListTaskDefinitionFamiliesOutput, bool) bool) error {
  	return c.ListTaskDefinitionFamiliesPagesWithContext(aws.BackgroundContext(), input, fn)
  }
docs: // ListTaskDefinitionFamiliesPages iterates over the pages of a ListTaskDefinitionFamilies operation,
  // calling the "fn" function with the response data for each page. To stop
  // iterating, return false from the fn function.
  //
  // See ListTaskDefinitionFamilies method for more information on how to use this operation.
  //
  // Note: This operation can generate multiple requests to a service.
  //
  //    // Example iterating over at most 3 pages of a ListTaskDefinitionFamilies operation.
  //    pageNum := 0
  //    err := client.ListTaskDefinitionFamiliesPages(params,
  //        func(page *ListTaskDefinitionFamiliesOutput, lastPage bool) bool {
  //            pageNum++
  //            fmt.Println(page)
  //            return pageNum <= 3
  //        })
  //