What is the test for granting a writ of habeas corpus?

"An appellate court receiving [a petition for a writ of habeas corpus] evaluates it by asking whether, assuming the petition's factual allegations are true, the petitioner would be entitled to relief. [Citations.] If no prima facie case for relief is stated, the court will summarily deny the petition. If, however, the court finds the factual allegations, taken as true, establish a prima facie case for relief, the court will issue an OSC [(order to show cause)]. [Citations.] . . . Issuance of an OSC, therefore, indicates the issuing court's preliminary assessment that the petitioner would be entitled to relief if his factual allegations are proved." (People v. Duvall (1995) 9 Cal.4th 464, 474-475.)