constructor

An Inherited Constructor

When you call
```
    $dp1 = Data::Presenter::SampleCensus->new()
```
... Perl notes that there is no subroutine called new() in Data::Presenter::SampleCensus.
Perl then asks: From whom does Data::Presenter::SampleCensus inherit?
The answer is found in @Data::Presenter::SampleCensus::ISA.
```
    @ISA = qw(Data::Presenter);
```