  
  import rest_framework
  from rest_framework import exceptions, serializers
  from rest_framework.compat import ProhibitNullCharactersValidator
  from rest_framework.fields import DjangoImageField, is_simple_callable
  
  # Tests for helper functions.
  # ---------------------------
  
  
 
</s>
from rest_framework.fields import (
    BuiltinSignatureError, DjangoImageField, is_simple_callable
)
  
  import rest_framework
  from rest_framework import exceptions, serializers
  from rest_framework.compat import ProhibitNullCharactersValidator
from rest_framework.fields import (
    BuiltinSignatureError, DjangoImageField, is_simple_callable
)
  
  # Tests for helper functions.
  # ---------------------------
  
  
keep keep keep keep replace keep keep keep keep keep
 Raise exception when field source is a built-in (#6766)
tests/test_fields.py