sub setDoctype {

   my XML::ValidWriter $self = &_self ;
   $self->{DOCTYPE} = shift if @_ ;
   return ;
}



sub _self {
   ## MUST be called as C< &_self ;>

   ## If it's a reference to anything but a plain old hash, then the
   ## first param is either an XML::ValidWriter, a reference to a glob
   ## a reference to a SCALAR, or a reference to an IO::Handle.
   return shift if ( @_ && ref $_[0] && isa( $_[0], 'XML::ValidWriter' ) ) ;
   my $callpkg = caller(1) ;
   croak "No default XML::ValidWriter declared for package '$callpkg'"
      unless $pkg_writers{$callpkg} ;
   return $pkg_writers{$callpkg} ;
}