IO provides a simple mechanism to load several of the IO modules
in one go. The IO modules belonging to the core are:

      IO::Handle
      IO::Seekable
      IO::File
      IO::Pipe
      IO::Socket
      IO::Dir
      IO::Select
      IO::Poll

Note that these modules should be loaded via

      use IO qw(Handle File); # etc.

and not via the deprecated method

      use IO;  # DEPRECATED