my $schema = Koha::Database->new->schema;
$schema->storage->txn_begin;
-use C4::Serials::Frequency;
+use C4::Serials::Frequency qw( GetSubscriptionFrequencies DelSubscriptionFrequency GetSubscriptionFrequency ModSubscriptionFrequency AddSubscriptionFrequency );
# Start by deleting all frequencies.
my @frequencies = GetSubscriptionFrequencies();