              raise
  
      def check_permissions(self, request):
          """
          Check if the request should be permitted.
          Raises an appropriate exception if the request is not permitted.
 
</s> remove from rest_framework.authentication import TokenAuthentication, BasicAuthentication, SessionAuthentication
 </s> add from rest_framework.authentication import (
    BaseAuthentication,
    TokenAuthentication,
    BasicAuthentication,
    SessionAuthentication
)
    def perform_authentication(self, request):
        """
        Perform authentication on the incoming request.

        Note that if you override this and simply 'pass', then authentication
        will instead be performed lazily, the first time either
        `request.user` or `request.auth` is accessed.
        """
        request.user

              raise
  
    def perform_authentication(self, request):
        """
        Perform authentication on the incoming request.

        Note that if you override this and simply 'pass', then authentication
        will instead be performed lazily, the first time either
        `request.user` or `request.auth` is accessed.
        """
        request.user

      def check_permissions(self, request):
          """
          Check if the request should be permitted.
          Raises an appropriate exception if the request is not permitted.
keep add keep keep keep keep
 Auth is no longer lazy.  Closes #667.

More consistent auth failure behavior. 
rest_framework/views.py