sub new {
    my ( $class, $cnf_file ) = @_;
    my $self = # construct your object
    $self->_initiaze;
}

sub _initialize {
    for my $issue ($self->_issues){
        while (my $article = $issue->_article){
            $self->_process($article);
        }
    }
    $self->_post_process;
}