Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_91 (ceased_to_be_duke_of_girona VARCHAR, heir_of VARCHAR)
### Question:
WHAT IS THE Ceased to be Duke of Girona THAT HAS PETER IV?
### Answer:
SELECT ceased_to_be_duke_of_girona FROM table_name_91 WHERE heir_of = "peter iv"