# File lib/text/format.rb, line 318
318:     def hyphenator=(h)
319:       raise ArgumentError, "#{h.inspect} is not a valid hyphenator." unless h.respond_to?(:hyphenate_to)
320:       arity = h.method(:hyphenate_to).arity
321:       raise ArgumentError, "#{h.inspect} must have exactly two or three arguments." unless [2, 3].include?(arity)
322:       @hyphenator = h
323:       @hyphenator_arity = arity
324:     end