normalize (ActiveSupport::Multibyte::Chars)

    # File lib/active_support/multibyte/chars.rb, line 404
          def normalize(form=ActiveSupport::Multibyte.default_normalization_form)
            # See http://www.unicode.org/reports/tr15, Table 1
            codepoints = self.class.u_unpack(@wrapped_string)
            chars(case form
              when :d
                self.class.reorder_characters(self.class.decompose_codepoints(:canonical, codepoints))
              when :c
                self.class.compose_codepoints(self.class.reorder_characters(self.class.decompose_codepoints(:canonical, codepoints)))
              when :kd
                self.class.reorder_characters(self.class.decompose_codepoints(:compatability, codepoints))
              when :kc
                self.class.compose_codepoints(self.class.reorder_characters(self.class.decompose_codepoints(:compatability, codepoints)))
              else
                raise ArgumentError, "#{form} is not a valid normalization variant", caller
            end.pack('U*'))
          end