What is the burden of proof under Proposition 47 of resentencing?

In People v. Sherow (2015) 239 Cal.App.4th 875 (Sherow), the court observed that "Proposition 47 does not explicitly allocate a burden of proof." (Id. at p. 878.) The court stated that "applying established principles of statutory construction we believe a petitioner for resentencing under Proposition 47 must establish his or her eligibility for such resentencing. In such cases, it is important to keep in mind a person . . . was validly convicted under the law applicable at the time of the trial of the felony offenses. It is a rational allocation of burdens if the petitioner in such cases bears the burden of showing that he or she is eligible for resentencing of what was an otherwise valid sentence." (Id. at p. 878.)