How to use the pymars.reduce_model.trim function in pymars

species_retained = []
    for matrix in matrices:
        species_retained += trim_pfa(matrix, solution.species_names, species_targets, threshold)
    
    # want to ensure retained species are the set of those reachable for each state
    species_retained = list(set(species_retained))

    if previous_model and len(species_retained) == previous_model.model.n_species:
        return previous_model

    species_removed = [sp for sp in solution.species_names
                       if sp not in (species_retained + species_safe)
                       ]

    # Cut the exclusion list from the model.
    reduced_model = trim(model_file, species_removed, f'reduced_{model_file}')
    reduced_model_filename = soln2cti.write(
        reduced_model, f'reduced_{reduced_model.n_species}.cti', path=path
        )

    reduced_model_metrics = sample_metrics(
        reduced_model_filename, ignition_conditions, num_threads=num_threads, path=path
        )
    error = calculate_error(sampled_metrics, reduced_model_metrics)
    
    # If desired, now identify limbo species for future sensitivity analysis
    limbo_species = []
    if threshold_upper:
        species_retained += trim_pfa(
            matrix, solution.species_names, species_targets, threshold_upper
            )
        limbo_species = [

species_retained = []
    for matrix in matrices:
        species_retained += trim_drg(matrix, solution.species_names, species_targets, threshold)
    
    # want to ensure retained species are the set of those reachable for each state
    species_retained = list(set(species_retained))

    if previous_model and len(species_retained) == previous_model.model.n_species:
        return previous_model

    species_removed = [sp for sp in solution.species_names
                       if sp not in (species_retained + species_safe)
                       ]

    # Cut the exclusion list from the model.
    reduced_model = trim(model_file, species_removed, f'reduced_{model_file}')
    reduced_model_filename = soln2cti.write(
        reduced_model, f'reduced_{reduced_model.n_species}.cti', path=path
        )

    reduced_model_metrics = sample_metrics(
        reduced_model_filename, ignition_conditions, num_threads=num_threads, path=path
        )
    error = calculate_error(sampled_metrics, reduced_model_metrics)
    
    # If desired, now identify limbo species for future sensitivity analysis
    limbo_species = []
    if threshold_upper:
        species_retained += trim_drg(
            matrix, solution.species_names, species_targets, threshold_upper
            )
        limbo_species = [

num_threads : int, optional
        Number of CPU threads to use for performing simulations in parallel.
        Optional; default = 1, in which the multiprocessing module is not used.
        If 0, then use the available number of cores minus one. Otherwise,
        use the specified number of threads.
    
    Returns
    -------
    species_errors : numpy.ndarray
        Maximum errors induced by removal of each limbo species

    """
    species_errors = np.zeros(len(species_limbo))
    with TemporaryDirectory() as temp_dir:
        for idx, species in enumerate(species_limbo):
            test_model = trim(
                starting_model.filename, [species], f'reduced_model_{species}.cti', 
                phase_name=phase_name
                )
            test_model_file = soln2cti.write(
                test_model, f'reduced_model_{species}.cti', path=temp_dir
                )
            reduced_model_metrics = sample_metrics(
                test_model_file, ignition_conditions, phase_name=phase_name, 
                num_threads=num_threads
                )
            species_errors[idx] = calculate_error(metrics, reduced_model_metrics)
    
    return species_errors

Return reduced model and associated metadata

    """
    solution = ct.Solution(model_file, phase_name)
    species_removed = [sp for sp in solution.species_names
                       if importance_coeffs[sp] < threshold 
                       and sp not in species_safe
                       ]
    
    if (previous_model and 
        len(species_removed) == solution.n_species - previous_model.model.n_species
        ):
        return previous_model

    # Cut the exclusion list from the model.
    reduced_model = trim(
        model_file, species_removed, f'reduced_{model_file}', phase_name=phase_name
        )
    reduced_model_filename = soln2cti.write(
        reduced_model, f'reduced_{reduced_model.n_species}.cti', path=path
        )

    reduced_model_metrics = sample_metrics(
        reduced_model_filename, ignition_conditions, phase_name=phase_name, 
        num_threads=num_threads, path=path
        )
    error = calculate_error(sampled_metrics, reduced_model_metrics)

    return ReducedModel(
        model=reduced_model, filename=reduced_model_filename, error=error
        )

# this will be the only evaluation.
    species_errors = evaluate_species_errors(
        current_model, ignition_conditions, initial_metrics, species_limbo, 
        phase_name=phase_name, num_threads=num_threads
        )

    # Use a temporary directory to avoid cluttering the working directory with
    # all the temporary model files
    with TemporaryDirectory() as temp_dir:
        while species_limbo:
            # use difference between error and current error to find species to remove
            idx = np.argmin(np.abs(species_errors - current_model.error))
            species_errors = np.delete(species_errors, idx)
            species_remove = species_limbo.pop(idx)

            test_model = trim(
                current_model.filename, [species_remove], f'reduced_model_{species_remove}.cti', 
                phase_name=phase_name
                )
            test_model_file = soln2cti.write(
                test_model, output_filename=f'reduced_model_{species_remove}.cti', path=temp_dir
                )

            reduced_model_metrics = sample_metrics(
                test_model_file, ignition_conditions, phase_name=phase_name, 
                num_threads=num_threads, path=path
                )
            error = calculate_error(initial_metrics, reduced_model_metrics)

            logging.info(f'{test_model.n_species:^17} | {species_remove:^17} | {error:^.2f}')

            # Ensure new error isn't too high