def METHOD_NAME(root_folder):
    url = 'https://prod-dcd-datasets-cache-zipfiles.s3.eu-west-1.amazonaws.com/7kd5wj7v7p-3.zip'
    zip_filename = os.path.join(root_folder, 'notebooks', 'data', '7kd5wj7v7p-3.zip')
    data_folder = os.path.join(root_folder, 'notebooks', 'data')
    extracted_folder = os.path.join(data_folder, '7kd5wj7v7p-3', 'IXI_sample')
    # Extract if ZIP exists but not folder
    if not os.path.exists(zip_filename):
        # Download if it does not exist
        download_file(url, zip_filename)
    # Check if extracted folder exists
    if os.path.isdir(extracted_folder):
        print(f'Dataset folder already exists in {extracted_folder}')
        return extracted_folder
    assert has_correct_checksum_md5(zip_filename, 'eecb83422a2685937a955251fa45cb03')
    with ZipFile(zip_filename, 'r') as zip_obj:
        zip_obj.extractall(data_folder)
    assert os.path.isdir(extracted_folder)
    return extracted_folder