我不能在Perl 6中的类中调用私有方法：
class MyClass {
method !my-private-method($var1) {
# ....
}
method my-method() {
my $my-var1 = !my-private-method(123); # not found (Undeclared routines)
my $my-var1 = $!my-private-method(123); # not found (Undeclared routines)
my $my-var1 = $.my-private-method(123); # not found (Undeclared routines)
my $my-var1 = my-private-method(123); # not found (Undeclared routines)
那么如何从my-method调用my-private-method呢？