What is the effect of a common law rule of completeness on a witness in evidence?

This provision "is sometimes referred to as the statutory version of the common law rule of completeness. [Citation.] According to the common law rule: ' "[T]he opponent, against whom a part of an utterance has been put in, may in his turn complement it by putting in the remainder, in order to secure for the tribunal a complete understanding of the total tenor and effect of the utterance." [Citation.]' [Citation.]" (People v. Parrish (2007) 152 Cal.App.4th 263, 269, fn. 3.) The purpose of the rule "is to prevent the use of selected aspects of a conversation, act, declaration, or writing, so as to create a misleading impression on the subjects addressed. [Citation.] Thus, if a party's oral admissions have been introduced in evidence, he may show other portions of the same interview or conversation, even if they are self-serving, which 'have some bearing upon, or connection with, the admission . . . in evidence.' [Citations.]" (People v. Arias (1996) 13 Cal.4th 92, 156.)