# in Alpha.pm

   sub sayhowdy {
     my $self = shift;
     my $string = q{};
     open my $fh, ">", \$string;
     print $fh "Howdy, alpha\n";
     close $fh;
     return $string;
   }

   # in Beta.pm

   sub sayhowdy {
     my $self = shift;
     my $string = q{};
     open my $fh, ">", \$string;
     print $fh "Howdy, beta\n";
     close $fh;
     return $string;
   }