Description:

This module tells its users that functions in the FOOBAR package are to be
autoloaded from after the '__DATA__' token. See also the
perlsub/"Autoloading" manpage.

The __DATA__ token
The '__DATA__' token tells the perl compiler that the perl code for
compilation is finished. Everything after the '__DATA__' token is
available for reading via the filehandle FOOBAR::DATA, where FOOBAR is
the name of the current package when the '__DATA__' token is reached.
This works just the same as '__END__' does in package 'main', but for
other modules data after '__END__' is not automatically retrievable,
whereas data after '__DATA__' is. The '__DATA__' token is not
recognized in versions of perl prior to 5.001m.

Note that it is possible to have '__DATA__' tokens in the same package
in multiple files, and that the last '__DATA__' token in a given
package that is encountered by the compiler is the one accessible by
the filehandle. This also applies to '__END__' and main, i.e. if the
'main' program has an '__END__', but a module 'require'd (_not_ 'use'd)
by that program has a 'package main;' declaration followed by an
''__DATA__'', then the 'DATA' filehandle is set to access the data
after the '__DATA__' in the module, _not_ the data after the '__END__'
token in the 'main' program, since the compiler encounters the
'require'd file later.