sub parse {
  my $self = shift;
  my $arg = shift;
  croak "Parse already in progress (Expat)" if $self->{_State_};
  $self->{_State_} = 1;
  my $parser = $self->{Parser};
  my $ioref;
  my $result = 0;

  if (defined $arg) {
    if (ref($arg) and UNIVERSAL::isa($arg, 'IO::Handle')) {
      $ioref = $arg;
    } elsif (tied($arg)) {
      my $class = ref($arg);
      no strict 'refs';
      $ioref = $arg if defined &{"${class}::TIEHANDLE"};
    }
    else {
      eval {
        $ioref = *{$arg}{IO};  # This is line 456
      };
      undef $@;
    }
  }