text: class MobileConverter:
      regex = '1[3-9]\d{9}'
  
      def to_python(self, value):
          return str(value)
  
      def to_url(self, value):
          return str(value)
  
  
  class UserNameConverter:
      regex = '[a-zA-Z0-9_-]{5,20}'
  
      def to_python(self, value):
          return str(value)
  
      def to_url(self, value):
          return str(value)
  