599     except error.InterventionRequired:

   599     except error.InterventionRequired:

   600         tr.close()

   600         tr.close()

   601         raise

   601         raise

   602     finally:

   602     finally:

   603         tr.release()

   603         tr.release()

   604 

   608 

   605 class _lrucachenode(object):

   609 class _lrucachenode(object):

   606     """A node in a doubly linked list.

   610     """A node in a doubly linked list.

   607 

   611 

   608     Holds a reference to nodes on either side as well as a key-value

   612     Holds a reference to nodes on either side as well as a key-value