sub _close {
  my $data = shift;
  my $ftp  = ${*$data}{'net_ftp_cmd'};

  $data->SUPER::close();

  delete ${*$ftp}{'net_ftp_dataconn'} ################# LINE 54
    if exists ${*$ftp}{'net_ftp_dataconn'}
    && $data == ${*$ftp}{'net_ftp_dataconn'};