method postcircumfix:<( )>($c) {
        my @result = $.eigenstates.map({ $^code(|$c) });
        Junction.new(@result, type => self!type);
    }

##</code><code>##

my $k = $j2 );
my $k = $j( {^c != 2} );

# But both generated the message .. 

invoke() not implemented in class 'Integer'