Filter :class:`.Publication` objects using settings declared in
    :mod:`~harvester.settings` submodule.

    Args:
        publication (obj): :class:`.Publication` instance.

    Returns:
        obj/None: None if the publication was found in Aleph or `publication` \
                  if not.

def filter_publication(publication):
    """
    Filter :class:`.Publication` objects using settings declared in
    :mod:`~harvester.settings` submodule.

    Args:
        publication (obj): :class:`.Publication` instance.

    Returns:
        obj/None: None if the publication was found in Aleph or `publication` \
                  if not.
    """
    if settings.USE_DUP_FILTER:
        publication = dup_filter.filter_publication(publication)

    if publication and settings.USE_ALEPH_FILTER:
        publication = aleph_filter.filter_publication(
            publication,
            cmp_authors=settings.ALEPH_FILTER_BY_AUTHOR
        )

    return publication