user: Question: Who wrote the episode with E4515 as the production code?
Columns: ['Season no.', 'Series no.', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 46.0, '"Undaunted Mettle"', 'Steve Shill', 'René Balcer & Stephanie Sengupta', 'September28,2003', 'E4502']
SQL:

assistant: SELECT "Written by" FROM "Table" WHERE "Production code" = 'E4515';