  
          # In addition to regular validation we also ensure no additional fields are being passed in...
          unknown_fields = seen_fields_set - (form_fields_set | allowed_extra_fields_set)
  
          # Check using both regular validation, and our stricter no additional fields rule
          if bound_form.is_valid() and not unknown_fields:
              # Validation succeeded...
              cleaned_data = bound_form.cleaned_data
  
 
</s> remove         """Create a new highlighed snippet and return it's location.
        For the purposes of the sandbox example, also ensure we delete the oldest snippets if we have > MAX_FILES."""
 </s> add         """
        Create a new highlighed snippet and return it's location.
        For the purposes of the sandbox example, also ensure we delete the oldest snippets if we have > MAX_FILES.
        """ </s> remove  
 </s> add     # Auto-register new ModelResource classes into _model_to_resource 
    #__metaclass__ = _RegisterModelResource

        unknown_fields = unknown_fields - set(('csrfmiddlewaretoken',))
  
          # In addition to regular validation we also ensure no additional fields are being passed in...
          unknown_fields = seen_fields_set - (form_fields_set | allowed_extra_fields_set)
        unknown_fields = unknown_fields - set(('csrfmiddlewaretoken',))
  
          # Check using both regular validation, and our stricter no additional fields rule
          if bound_form.is_valid() and not unknown_fields:
              # Validation succeeded...
              cleaned_data = bound_form.cleaned_data
  
keep keep add keep keep keep keep keep keep
 Fixing some of the last blocking issues 
djangorestframework/resources.py