Which athlete had a six month suspension from IIHF?
CREATE TABLE "players_who_have_tested_positive_for_ban" (
  "athlete" text,
  "nation" text,
  "olympics" real,
  "substance" text,
  "punishment" text
);
SELECT "athlete" FROM "players_who_have_tested_positive_for_ban" WHERE "punishment"='six month suspension from iihf';