user: Question: What is the comissioned for 4 May 1943?
Columns: ['Name', 'Pennant', 'Builder', 'Laid Down', 'Launched', 'Commissioned', 'Fate']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Amethyst', 'U16', 'Alex. Stephen , Linthouse', '25 March 1942', '7 May 1943', '2 November 1943', 'Broken up 18 January 1957.']
SQL:

assistant: SELECT "Commissioned" FROM "Table" WHERE "Laid Down" = '4 May 1943';