sub AUTOLOAD {
  my $self = $_[ 0 ];
  ( my $name = our $AUTOLOAD ) =~ s/.*:://;
  return if $name eq 'DESTROTY';
  die "Unknown field: $name" unless exists $self->{ $name };
  no strict 'refs';
  *$AUTOLOAD = sub { my $self = shift;
                 return @_ ? $self->{ $name } = shift : $self->{ $name };
               };
  goto &$AUTOLOAD;
}