how ugly can we make a callback demo?

gistfile1.txt

my %gc  := nqp::jvmbootinterop('org.perl6.nqp.runtime.GlobalContext');
my %thr := nqp::jvmbootinterop('java.lang.Thread');
my %bji := nqp::jvmbootinterop('org.perl6.nqp.runtime.BootJavaInterop');
my %cls := nqp::jvmbootinterop('java.lang.Class');

my $gc_get_bji := %gc<getfield:bootInterop;Lorg/perl6/nqp/runtime/BootJavaInterop;>;
my $bji_implement := %bji<method:implementClass(Lorg/perl6/nqp/sixmodel/SixModelObject;Lorg/perl6/nqp/runtime/ThreadContext;)Lorg/perl6/nqp/sixmodel/SixModelObject;>;
my $cls_new := %cls<method:newInstance()Ljava/lang/Object;>;
my $thr_run := %thr<method:start()V>;

$thr_run(
    $cls_new(
        $bji_implement(
            $gc_get_bji(
                nqp::null(), # current GC
            ),
            [ ['extends','java.lang.Thread'], ['instance_method', 'run', '()V', method () { say("Hello thread") }] ],
            nqp::null(), # current TC
        ),
    ),
);