You have to keep testing it and go back and forth to the code

asteroid_spawner.py

@@ -2,3 +2,21 @@
 # -------------------
 # By MWC Contributors
 # This module defines an AsteroidSpawner agent class.
+from random import randint
+from asteroid import Asteroid
+
+class AsteroidSpawner:
+    display = False
+
+    def __init__(self, board_size):
+        width, height = board_size
+        self.board_width = width
+
+    def play_turn(self, game):
+        game.state['score'] += 1
+        if self.should_spawn_asteroid(game.turn_number):
+            asteroid = Asteroid((randint(0, self.board_width - 1), 0))
+            game.add_agent(asteroid)
+
+    def should_spawn_asteroid(self, turn_number):
+        return randint(0, 1000) < turn_number