.?method calls a method if it is defined. If the object does not have a method with the given name, Nil is returned.
class C {
method m() {'m'}
}
my $c = C.new();
say $c.?m(); # m
say $c.?n(); # Nil
📘 Method postfix operator .? in Raku
N. B. Perl 6 has been renamed to Raku. Click to read more.