1package My::PingPong; 2 3sub new { 4 my $self = shift; 5 my $class = ref($self) || $self; 6 bless {_num=>shift} => $class; 7} 8 9sub next { 10 my $self = shift; 11 $self->{_num}++; 12} 13 14sub value { 15 my $self = shift; 16 $self->{_num}; 17} 18 191;