def MAY(m)
      RequirementLevel::Low.new(m, false, subject, *challenges).result
    end
def MAY(m)
      RequirementLevel::Low.new(m, false, subject, *challenges).result
    end
This word, or the adjective "OPTIONAL", mean that an item is
 truly optional.  One vendor may choose to include the item because a
 particular marketplace requires it or because the vendor feels that
 it enhances the product while another vendor may omit the same item.
 An implementation which does not include a particular option MUST be
 prepared to interoperate with another implementation which does
 include the option, though perhaps with reduced functionality. In the
 same vein an implementation which does include a particular option
 MUST be prepared to interoperate with another implementation which
 does not include the option (except, of course, for the feature the
 option provides.)

 @example _Optional_ definition
   it { 'foo'.bar }.MAY match /^foo$/

 @param m [#matches?] The matcher.

 @return [Result::Fail, Result::Pass] Report if the spec pass or fail.