When 1008/1009 is the production code how many directors are there?
CREATE TABLE "table1_1854728_2" (
  "no_in_series" text,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "air_date" text,
  "production_code" text
);
SELECT COUNT("directed_by") FROM "table1_1854728_2" WHERE "production_code"='1008/1009';