(defcustom completion-cycle-threshold nil
"Number of completion candidates below which cycling is used.
Depending on this setting `completion-in-region' may use cycling,
-like `minibuffer-force-complete'.
+whereby invoking a completion command several times in a row
+completes to each of the candidates in turn, in cyclic manner.
If nil, cycling is never used.
If t, cycling is always used.
If an integer, cycling is used so long as there are not more