class Gem::OptionParser::List

append(switch, short_opts, long_opts, nolong_opts)

+nolong_opts+:: List of long style options with "no-" prefix.
+long_opts+:: List of long style options.
+short_opts+:: List of short style options.
+switch+:: Gem::OptionParser::Switch instance to be inserted.

and negated long options. Arguments are:
Appends +switch+ at the tail of the list, and associates short, long

def append(*args)
  update(*args)
  @list.push(args[0])
end