text: from __future__ import unicode_literals
  import base64
  from django.db import models
  try:
      from django.utils.encoding import force_bytes
  except:
      pass
  from django.utils.encoding import smart_bytes, smart_text
  from django.utils.encoding import DjangoUnicodeDecodeError
  
  
  
  class Base64Field(models.TextField):
  
      def to_python(self, value):
          if value is None:
              return None
  
          decoded = base64.b64decode(value)
          return smart_text(decoded)
  
      def get_prep_value(self, value):
          if value is None:
              return None
          value = smart_text(base64.b64encode(smart_bytes(value)))
          return self.to_python(value)
  
  
  