Assertion Consumer 

my $sp = Authen::NZigovt->class_for('service_provider')->new(
    conf_dir => $path_to_igovt_conf_dir,
);

my $resp = $sp->resolve_artifact(     # throws exception on error
    artifact   => $data->{SAMLart},
    request_id => $state->{igovt_request_id},
);

my $flt = $resp->{flt}