Test pure-Python LL entities everywhere.

BTrees/check.py

@@ -41,6 +41,7 @@ from BTrees.IOBTree import IOBTreePy, IOBucketPy, IOSetPy, IOTreeSetPy
 from BTrees.LFBTree import LFBTree, LFBucket, LFSet, LFTreeSet
 from BTrees.LFBTree import LFBTreePy, LFBucketPy, LFSetPy, LFTreeSetPy
 from BTrees.LLBTree import LLBTree, LLBucket, LLSet, LLTreeSet
+from BTrees.LLBTree import LLBTreePy, LLBucketPy, LLSetPy, LLTreeSetPy
 from BTrees.LOBTree import LOBTree, LOBucket, LOSet, LOTreeSet
 from BTrees.OIBTree import OIBTree, OIBucket, OISet, OITreeSet
 from BTrees.OIBTree import OIBTreePy, OIBucketPy, OISetPy, OITreeSetPy