How to use the fitlins.utils.bids.BIDSError function in fitlins

def __init__(self, message, bids_root):
        indent = 10
        header = '{sep} BIDS root folder: "{bids_root}" {sep}'.format(
            bids_root=bids_root, sep=''.join(['-'] * indent))
        self.msg = '\n{header}\n{indent}{message}\n{footer}'.format(
            header=header, indent=''.join([' '] * (indent + 1)),
            message=message, footer=''.join(['-'] * len(header))
        )
        super(BIDSError, self).__init__(self.msg)
        self.bids_root = bids_root

if not participant_label:
        return all_participants

    # Drop sub- prefixes
    participant_label = [sub[4:] if sub.startswith('sub-') else sub for sub in participant_label]

    found_label = layout.get_subjects(subject=participant_label)

    if not found_label:
        raise BIDSError('Could not find participants [{}]'.format(
            ', '.join(participant_label)), bids_dir)

    # Warn if some IDs were not found
    notfound_label = sorted(set(participant_label) - set(found_label))
    if notfound_label:
        exc = BIDSError('Some participants were not found: {}'.format(
            ', '.join(notfound_label)), bids_dir)
        if strict:
            raise exc
        warnings.warn(exc.msg, BIDSWarning)

    return found_label

['02']

    >>> collect_participants('ds114', participant_label=['02', '14'],
    ...                      strict=True)  # doctest: +IGNORE_EXCEPTION_DETAIL
    Traceback (most recent call last):
    fmriprep.utils.bids.BIDSError:
    ...


    """
    layout = BIDSLayout(bids_dir)
    all_participants = layout.get_subjects()

    # Error: bids_dir does not contain subjects
    if not all_participants:
        raise BIDSError(
            'Could not find participants. Please make sure the BIDS data '
            'structure is present and correct. Datasets can be validated online '
            'using the BIDS Validator (http://incf.github.io/bids-validator/).\n'
            'If you are using Docker for Mac or Docker for Windows, you '
            'may need to adjust your "File sharing" preferences.', bids_dir)

    # No --participant-label was set, return all
    if not participant_label:
        return all_participants

    # Drop sub- prefixes
    participant_label = [sub[4:] if sub.startswith('sub-') else sub for sub in participant_label]

    found_label = layout.get_subjects(subject=participant_label)

    if not found_label:

'structure is present and correct. Datasets can be validated online '
            'using the BIDS Validator (http://incf.github.io/bids-validator/).\n'
            'If you are using Docker for Mac or Docker for Windows, you '
            'may need to adjust your "File sharing" preferences.', bids_dir)

    # No --participant-label was set, return all
    if not participant_label:
        return all_participants

    # Drop sub- prefixes
    participant_label = [sub[4:] if sub.startswith('sub-') else sub for sub in participant_label]

    found_label = layout.get_subjects(subject=participant_label)

    if not found_label:
        raise BIDSError('Could not find participants [{}]'.format(
            ', '.join(participant_label)), bids_dir)

    # Warn if some IDs were not found
    notfound_label = sorted(set(participant_label) - set(found_label))
    if notfound_label:
        exc = BIDSError('Some participants were not found: {}'.format(
            ', '.join(notfound_label)), bids_dir)
        if strict:
            raise exc
        warnings.warn(exc.msg, BIDSWarning)

    return found_label