invalid_localhost test in helo plugin? (1 message)

How can this ever pass when receiving mail from the outside?

sub invalid_localhost {
my ($self, $host) = @_;
if ($self->is_localhost($self->qp->connection->remote_ip)) {
$self->log(LOGDEBUG, "pass, is localhost");
return;
}
if ($host && lc $host eq 'localhost') {
$self->log(LOGDEBUG, "pass, host is localhost");
return;
};

#$self->log( LOGINFO, "fail, not localhost" );
return "You are not localhost", "invalid localhost";
}

What is the relation between the helo and fcrdns plugins? Isn't helo doing everything and more than fcrdns does?