(a) When the jury has agreed upon a verdict, they shall be conducted into court by the officer having them in charge. When they appear in court, they shall be asked by the judge, whether they have agreed upon their verdict, and if the foreman answers in the affirmative, they shall declare the same. The verdict shall be unanimous. (b) When a verdict is returned, before it is recorded, the jury shall be polled at the request of any party or upon the court's own motion. If upon the poll there is not unanimous concurrence, the jury may be directed to retire for further deliberation or may be discharged pursuant to § 105.22. NOTE: Section 105.30 continues the substance of Subdivisions (a) and (d) of former Rule 31. See also Cal. Pen. Code §§ 1147, 1149, 1163, 1164. See generally 8 Moore, Federal Practice &&31.02, 3107 (1974); B. Witkin, California Criminal Procedure Judgment and Attack in Trial Court §§ 530-531 (1963, Supp. 1973).