content_type=

# File actionpack/lib/action_dispatch/http/response.rb, line 226
    def content_type=(content_type)
      return unless content_type
      new_header_info = parse_content_type(content_type.to_s)
      prev_header_info = parsed_content_type_header
      charset = new_header_info.charset || prev_header_info.charset
      charset ||= self.class.default_charset unless prev_header_info.mime_type
      set_content_type new_header_info.mime_type, charset
    end