CREATE TABLE table_73845 ("Season no." FLOAT, "Series no." FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" CLOB)

Who wrote the episode with e4515 as the production code?
SELECT "Written by" FROM table_73845 WHERE "Production code" = 'E4515'
SELECT "Written by" FROM "table_73845" WHERE "Production code" = 'E4515'