In Municipal Court v. Superior Court (Gonzalez) (1993) 5 Cal. 4th 1126 22 Cal. Rptr. 2d 504, 857 P.2d 325, the Supreme Court considered a petition for a writ of mandate brought by the municipal court against the superior court's ruling granting a criminal defendant's habeas corpus petition. In Gonzalez the municipal court had a policy of assigning court commissioners to determine whether probable cause existed to detain the defendants arrested without warrants. Gonzalez challenged his detention under this policy, and the superior court granted him habeas corpus relief. Thereafter, the municipal court instituted a writ proceeding. The Gonzalez court held that the lower court lacked standing to initiate a writ proceeding. The Supreme Court reasoned: " 'In our common law judicial system we rely upon a separation of roles to bring about the proper results. The courts' role is to decide cases; the parties' role is to bring cases before the courts. If a party is aggrieved by the ruling of the lower court, he is provided with an avenue of appeal to a higher tribunal by means of an orderly prescribed procedure . . . . the premise under which the judiciary operates is straightforward: if no individual party finds it worth his or her while to champion the cause and seek judicial review, then review will not occur.' " (5 Cal. 4th at p. 1131.)