What is the test for pleading not stating "facts sufficient to constitute a cause of action"?

pleading not stating " 'facts sufficient to constitute a cause of action, the rule is that if, upon a consideration of all the facts stated, it appears that the plaintiff is entitled to any relief at the hands of the court against the defendants, the complaint will be held good, although the facts may not be clearly stated or may be intermingled with a statement of other facts irrelevant to the cause of action shown, or although the plaintiff may demand relief to which he is not entitled under the facts alleged.' [Citation.] In other words, 'plaintiff need only plead facts showing that he may be entitled to some relief (citation).' [Citation.] Furthermore, we are not concerned with plaintiff's possible inability or difficulty in proving the allegations of the complaint. [Citation.]" (Gruenberg v. Aetna Ins. Co. (1973) 9 Cal.3d 566, 572.)