What is the test for a finding of reasonable and probable cause in a prohibition proceeding?

It is true that when the inquiry is whether or not the evidence adduced at the preliminary examination supports the magistrate's finding of reasonable and probable cause, a court in a prohibition proceeding does not undertake to weigh the evidence (if there be some supporting evidence), nor is it concerned with mere irregularities of procedure before the magistrate, nor, in general, with the correctness of his rulings on the admissibility of evidence. See Rogers v. Superior Court, 46 Cal.2d 3, 7-8, 291 P.2d 929; Badillo v. Superior Court, 46 Cal.2d 269, 271-272, 294 P.2d 23.