code: def content_charset
        content_types.each do |value|
          if value.include?(';')
            value.split(';').each do |param|
              param.strip!
  
              if param.start_with?('charset=')
                return param.split('=',2).last
              end
            end
          end
        end
  
        return nil
      end
docs: The charset included in the Content-Type.
  
   @return [String, nil]
     The charset of the content.
  
   @since 0.4.0