Consequences are undefined if HASH-TABLE is mutated during execution of BODY,
except for changing or removing elements corresponding to the current key. The
-applies to all threads, not just the curren one -- even for synchronized
+applies to all threads, not just the current one -- even for synchronized
hash-tables. If the table may be mutated by another thread during iteration,
use eg. SB-EXT:WITH-LOCKED-HASH-TABLE to protect the WITH-HASH-TABLE-ITERATOR
for."