Atomically return and remove the first (LPOP) or last (RPOP) element of the list. For example
if the list contains the elements "a","b","c" RPOP will return "c" and the list will become
"a","b".
<p>
If the key does not exist or the list is already empty the special value 'nil' is returned.
@see #lpop(string)
@param key
@return Bulk reply
Atomically return and remove the first (LPOP) or last (RPOP) element of the list. For example if the list contains the elements "a","b","c" RPOP will return "c" and the list will become "a","b". <p> If the key does not exist or the list is already empty the special value 'nil' is returned. @see #lpop(string) @param key @return Bulk reply