=cut
sub source {
- my ($self, $moniker) = @_;
+ my $self = shift;
+
+ $self->throw_exception("source() expects a source name")
+ unless @_;
+
+ my $moniker = shift;
+
my $sreg = $self->source_registrations;
return $sreg->{$moniker} if exists $sreg->{$moniker};