def title=(title)
      @title = title.to_s.strip.upcase
      @title << 'M' if @title.match(/[A-LN-Z]$/)
      @title = 'IM' if @title == 'M'
      @title = 'WIM' if @title == 'WM'
      @title = nil if @title == ''
      raise "invalid chess title (#{title})" unless @title.nil? || @title.match(/^W?[GIFCN]M$/)
    end
def title=(title)
      @title = title.to_s.strip.upcase
      @title << 'M' if @title.match(/[A-LN-Z]$/)
      @title = 'IM' if @title == 'M'
      @title = 'WIM' if @title == 'WM'
      @title = nil if @title == ''
      raise "invalid chess title (#{title})" unless @title.nil? || @title.match(/^W?[GIFCN]M$/)
    end
Chess title. Is either unknown (nil) or one of: _GM_, _IM_, _FM_, _CM_, _NM_,
 or any of these preceeded by the letter _W_.