In what circumstances will counsel withdraw from a habeas corpus petition?

In Finley, the defendant was convicted of murder, and the conviction was affirmed on appeal. The defendant then filed a petition for habeas corpus, and counsel was appointed for her under a Pennsylvania law which entitled her to appointed counsel in habeas corpus proceedings. After reviewing the record, counsel informed the court he had found no potentially meritorious issues and requested leave to withdraw. The trial court reviewed the record, agreed there were no meritorious issues and dismissed the petition. (Pennsylvania v. Finley, supra, 481 U.S. at pp. 553-554, 107 S.Ct. at pp. 1992-1993.) The defendant contended she was entitled to have her attorney file a brief in the form required by Anders. (Ibid.)