CPAN::Groonga

   indexpageids => 1,
                    generator => $generator,
                    format => "json"
                };
                if(defined $namespace_key){
                    $a->{ $namesp

  my $a = {
                            action => "query",
                            format => "json",
                            pageids => $pageid,
                            prop => "revisions"

y, and cannot be overwritten:

action = "query"
indexpageids = 1
generator = <generate>
format = "json"

Additional parameters can be set in the constructor argument 'args'.
Arguments for a generator