BEGIN {
   my $backend;
   if    ($] >= 5.010) { $backend = 'Data::Manip::Perl5010'; }
   elsif ($] >= 5.008) { $backend = 'Data::Manip::Perl5008'; }
   elsif ($] >= 5.006) { $backend = 'Data::Manip::Perl5006'; }
   else { die("Perl $] isn't supported\n"); }
   eval "require $backend" or die $@;
   our @ISA = $backend;
}