use Test;BEGIN { plan(tests => 1) }skip(! $ENV{NP_DO_TEST} ? 'Skip since env variable NP_DO_TEST=0' : '', sub {   my $ok;   use Net::Packet::Env qw($Env);   use Net::Packet::Consts qw(:eth :arp);   $Env->dev($ENV{NP_ETH_DEV});   $Env->ip ($ENV{NP_ETH_IP});   $Env->mac($ENV{NP_ETH_MAC});   $Env->debug(3) if $ENV{NP_DEBUG};   require Net::Packet::ETH;   require Net::Packet::ARP;   require Net::Packet::Frame;   my $l2 = Net::Packet::ETH->new(      type => NP_ETH_TYPE_ARP,   );   my $l3 = Net::Packet::ARP->new(      opCode => NP_ARP_OPCODE_REQUEST,      dstIp  => $ENV{NP_ETH_TARGET_IP},   );   my $frame = Net::Packet::Frame->new(l2 => $l2, l3 => $l3);   $frame->send;   until ($Env->dump->timeout) {      if ($frame->recv) {         $ok++;         last;      }   }   $Env->dump->stop;   $Env->dump->clean;   $ok;});