You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: replay_flag.rs
    path of file: ./repos/sdk-core/core/src/core_tests
    
    the code of the file until where you have to start completion: use crate::{
    test_help::{
        build_fake_sdk, build_mock_pollers, canned_histories, hist_to_poll_resp, mock_worker,
        MockPoll
    
fn fire_happy_hist(num_timers: u32) -> Worker {
    let func = timers_wf(num_timers);
    // Add 1 b/c history takes # wf tasks, not timers
    let t = canned_histories::long_sequential_timers(num_timers as usize);
    let mut worker = build_fake_sdk(MockPollCfg::from_resps(t, [ResponseType::AllHistory]));
    worker.register_wf(DEFAULT_WORKFLOW_TYPE, func);
    worker
}