Example

  eval {
      my $url="zzz";
      $response = $ua->get($url);
      if ($response->is_success) {  
    $content=$response->content;
      } else {
    next;
      }      
      $te= HTML::TableExtract->new(keep_html=>0);
      $te->parse($content);
      if ($te->table(3,3)->cell(1,0) eq "xxxx") {
    $a=$te->table(3,3)->cell(1,1);
    $b=$te->table(3,3)->cell(4,1);
      } else {
    $a=$te->table(3,4)->cell(1,1);
    $b=$te->table(3,4)->cell(4,1);
      }

    };
    warn  $@ if $@;
}
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$te->table(3,3) does not exist in all cases and thus I always use eval instead of a proper error handling.