user: Question: WHAT IS THE Ceased to be Duke of Girona THAT HAS Peter IV?
Columns: ['Name', 'Heir of', 'Birth', 'Ceased to be Duke of Girona', 'Death']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Infante Juan later John I', 'Peter IV', '27 December 1350', '6 January 1387 became King', '19 May 1396']
SQL:

assistant: SELECT "Ceased to be Duke of Girona" FROM "Table" WHERE "Heir of" = 'Peter IV';