[O] How to make ~evil-leader~ work for for ~org-src-mode~?

[Ben]

Dear all,

I want to set some evil-leader keys for org-src-mode with the following
code:

(evil-leader/set-key-for-mode 'org-src-mode
    "k" 'org-edit-src-abort
    "s" 'org-edit-src-save
    "'" 'org-edit-src-exit)

But it doesn't work. Why is that?

Thanks,
Ben