Raise DefunctDatasetError (#9)

- Raise DefunctDatasetError (09b974af94093b848d9230b4929297e89e196458)

the_pile_books3.py

@@ -17,6 +17,7 @@
 """The BookCorpus dataset based on Shawn Presser's work https://github.com/soskek/bookcorpus/issues/27 """
 
 import datasets
+from datasets.exceptions import DefunctDatasetError
 
 
 _DESCRIPTION = """\
@@ -64,6 +65,9 @@ class ThePileBooks3(datasets.GeneratorBasedBuilder):
     DEFAULT_WRITER_BATCH_SIZE = 500
 
     def _info(self):
+        raise DefunctDatasetError(
+            "Dataset 'the_pile_books3' is defunct and no longer accessible due to reported copyright infringement"
+        )
         return datasets.DatasetInfo(
             description=_DESCRIPTION,
             features=datasets.Features(