What is aggressive rider Richie Porte's team classifaction?
CREATE TABLE "classification_leadership" (
  "stage" real,
  "winner" text,
  "general_classification" text,
  "mountains_classification" text,
  "sprint_classification" text,
  "young_rider_classification" text,
  "team_classification" text,
  "aggressive_rider" text
);
SELECT "team_classification" FROM "classification_leadership" WHERE "aggressive_rider"='Richie Porte';