append_if_string=

# File actionpack/lib/action_view/template/handlers/erb.rb, line 18
    def append_if_string=(value)
      if value.is_a?(String) && !value.is_a?(NonConcattingString)
        ActiveSupport::Deprecation.warn("<% %> style block helpers are deprecated. Please use <%= %>", caller)
        self << value
      end
    end