it('should correctly identify itself using the USER_AGENT in the request header', async () => {
    const secFetcher = new SECFetcher();
    const mockGet = jest.spyOn(axios, 'get').mockResolvedValue({ data: 'test data' });

    const url = 'https://www.sec.gov/test';
    const params = { param1: 'value1' };

    await secFetcher.request(url, params);

    expect(mockGet).toHaveBeenCalledWith(url, expect.objectContaining({
      headers: expect.objectContaining({
        'User-Agent': 'My Corp [email protected]'
      })
    }));

    mockGet.mockRestore();
  });

  it('should use gzip compression in the request header', async () => {
    const secFetcher = new SECFetcher();
    const mockGet = jest.spyOn(axios, 'get').mockResolvedValue({ data: 'test data' });

    const url = 'https://www.sec.gov/test';
    const params = { param1: 'value1' };

    await secFetcher.request(url, params);

    expect(mockGet).toHaveBeenCalledWith(url, expect.objectContaining({
      headers: expect.objectContaining({
        'Accept-Encoding': 'gzip, deflate, br'
      })
    }));

    mockGet.mockRestore();

  it('should handle multiple concurrent requests using requestBatch method', async () => {
    const secFetcher = new SECFetcher();
    const mockResponses = [
      { data: 'response 1' },
      { data: 'response 2' },
      { data: 'response 3' }
    ];
    const mockRequest = jest.spyOn(secFetcher, 'request')
      .mockImplementation((url, params) => Promise.resolve({ data: `response for ${url}` }));

    const urls = [
      { url: 'https://www.sec.gov/url1', params: { param1: 'value1' } },
      { url: 'https://www.sec.gov/url2', params: { param2: 'value2' } },
      { url: 'https://www.sec.gov/url3', params: { param3: 'value3' } }
    ];

    const result = await secFetcher.requestBatch(urls);

    expect(mockRequest).toHaveBeenCalledTimes(3);
    expect(mockRequest).toHaveBeenNthCalledWith(1, 'https://www.sec.gov/url1', { param1: 'value1' });
    expect(mockRequest).toHaveBeenNthCalledWith(2, 'https://www.sec.gov/url2', { param2: 'value2' });
    expect(mockRequest).toHaveBeenNthCalledWith(3, 'https://www.sec.gov/url3', { param3: 'value3' });
    expect(result).toEqual(['response for https://www.sec.gov/url1', 'response for https://www.sec.gov/url2', 'response for https://www.sec.gov/url3']);

    mockRequest.mockRestore();
  });

  it('should return an empty array if any request in requestBatch fails', async () => {
    const secFetcher = new SECFetcher();
    const mockRequest = jest.spyOn(secFetcher, 'request');

    mockRequest.mockResolvedValueOnce({ data: 'response 1' });
    mockRequest.mockRejectedValueOnce(new Error('Request failed'));
    mockRequest.mockResolvedValueOnce({ data: 'response 3' });

    const urls = [
      { url: 'https://www.sec.gov/url1', params: { param1: 'value1' } },
      { url: 'https://www.sec.gov/url2', params: { param2: 'value2' } },
      { url: 'https://www.sec.gov/url3', params: { param3: 'value3' } }
    ];

    const result = await secFetcher.requestBatch(urls);

    expect(mockRequest).toHaveBeenCalledTimes(3);
    expect(result).toEqual([]);

    mockRequest.mockRestore();
  });