Rules => {
        a => sub {
                     my ($filter,$element) = @_;
                     my $content = $element->{content};
                     my ($pre,$post) = ('','');
                     if ($content=~s{^\s*<br />}{}) {
                         $pre = '<br />';
                     }
                     if ($content=~s{<br />\s*$}{}) {
                         $post = '<br />';
                     }
                     if ($pre || $post) {
                         $element->{literal} = 
                              $pre.
                              '<a ' . $self->_hss_join_attribs( $element{attr} ) . '>'
                              . $content 
                              . '</a>'
                              . $post;
                     }
                     return 1;
                }
    }