Why ivy-immediate-done is not shown in counsel-M-x

Question

I realize that ivy-immediate-done is not shown in counsel-M-x. Since it's an interactive command, I'm assuming counsel-M-x somehow filters it from its result. But a quick search of the function name in its code directory fails to find the relevant logic. I'm wondering what I am missing here. Thx!

Answer 1

Found it! Don't know why I missed the first time.

Here's why: Code

(defun ivy-define-key (keymap key def)
  "Forward to (`define-key' KEYMAP KEY DEF).
Remove DEF from `counsel-M-x' list."
  (put def 'no-counsel-M-x t)
  (define-key keymap key def))