How many titles does the episode written by Joe Toplyn have?
CREATE TABLE "table1_25716397_1" (
  "series_no" real,
  "no_in_season" real,
  "title" text,
  "written_by" text,
  "directed_by" text,
  "original_air_date" text
);
SELECT COUNT("title") FROM "table1_25716397_1" WHERE "written_by"='Joe Toplyn';