Who directed the episode that had a production code of 2j5457?
CREATE TABLE "table1_25851971_1" (
  "no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_million" text
);
SELECT "directed_by" FROM "table1_25851971_1" WHERE "production_code"='2J5457';