package Filter::ISA;

use Filter::Simple;

FILTER_ONLY code => sub {
  if ( /package\s+(.+?)\s+isa\s+(.+?);/g ) {
    my $name = $1;
    my $base = $2;
    if ( $name !~ /;/ ) {
      $base =~ s/,/ /go;
      s/package $name isa (.+);/package $name; use base qw( $base );/o;
    }
  }
};

1;