code: public boolean hasShortOption(String opt)
      {
          opt = Util.stripLeadingHyphens(opt);
  
          return shortOpts.containsKey(opt);
      }
docs: Returns whether the named {@link Option} is a member of this {@link Options}.
  
  @param opt short name of the {@link Option}
  @return true if the named {@link Option} is a member of this {@link Options}
  @since 1.3