Launches training session.
    :param process_queue: Queue used to send signal back to main.
    :param sub_id: Unique id for training session.
    :param run_seed: Random seed used for training.
    :param run_options: Command line arguments for training.

def run_training(sub_id: int, run_seed: int, run_options, process_queue):
    """
    Launches training session.
    :param process_queue: Queue used to send signal back to main.
    :param sub_id: Unique id for training session.
    :param run_seed: Random seed used for training.
    :param run_options: Command line arguments for training.
    """
    # Docker Parameters
    docker_target_name = (run_options['--docker-target-name']
                          if run_options['--docker-target-name'] != 'None' else None)

    # General parameters
    env_path = (run_options['--env']
                if run_options['--env'] != 'None' else None)
    run_id = run_options['--run-id']
    load_model = run_options['--load']
    train_model = run_options['--train']
    save_freq = int(run_options['--save-freq'])
    keep_checkpoints = int(run_options['--keep-checkpoints'])
    base_port = int(run_options['--base-port'])
    num_envs = int(run_options['--num-envs'])
    curriculum_folder = (run_options['--curriculum']
                         if run_options['--curriculum'] != 'None' else None)
    lesson = int(run_options['--lesson'])
    fast_simulation = not bool(run_options['--slow'])
    no_graphics = run_options['--no-graphics']
    trainer_config_path = run_options['<trainer-config-path>']
    # Recognize and use docker volume if one is passed as an argument
    if not docker_target_name:
        model_path = './models/{run_id}-{sub_id}'.format(run_id=run_id, sub_id=sub_id)
        summaries_dir = './summaries'
    else:
        trainer_config_path = \
            '/{docker_target_name}/{trainer_config_path}'.format(
                docker_target_name=docker_target_name,
                trainer_config_path=trainer_config_path)
        if curriculum_folder is not None:
            curriculum_folder = \
                '/{docker_target_name}/{curriculum_folder}'.format(
                    docker_target_name=docker_target_name,
                    curriculum_folder=curriculum_folder)
        model_path = '/{docker_target_name}/models/{run_id}-{sub_id}'.format(
            docker_target_name=docker_target_name,
            run_id=run_id,
            sub_id=sub_id)
        summaries_dir = '/{docker_target_name}/summaries'.format(
            docker_target_name=docker_target_name)

    trainer_config = load_config(trainer_config_path)
    env_factory = create_environment_factory(
        env_path,
        docker_target_name,
        no_graphics,
        run_seed,
        base_port + (sub_id * num_envs)
    )
    env = SubprocessUnityEnvironment(env_factory, num_envs)
    maybe_meta_curriculum = try_create_meta_curriculum(curriculum_folder, env)

    # Create controller and begin training.
    tc = TrainerController(model_path, summaries_dir, run_id + '-' + str(sub_id),
                           save_freq, maybe_meta_curriculum,
                           load_model, train_model,
                           keep_checkpoints, lesson, env.external_brains,
                           run_seed, fast_simulation)

    # Signal that environment has been launched.
    process_queue.put(True)

    # Begin training
    tc.start_learning(env, trainer_config)