api: mark getCollisionMaps as nullable

runelite-api/src/main/java/net/runelite/api/Client.java

@@ -1425,6 +1425,7 @@ public interface Client extends GameEngine
 	 *
 	 * @return the collision data
 	 */
+	@Nullable
 	CollisionData[] getCollisionMaps();
 
 	@VisibleForDevtools

runelite-api/src/main/java/net/runelite/api/coords/WorldArea.java

@@ -295,6 +295,11 @@ public class WorldArea
 		}
 
 		CollisionData[] collisionData = client.getCollisionMaps();
+		if (collisionData == null)
+		{
+			return false;
+		}
+
 		int[][] collisionDataFlags = collisionData[plane].getFlags();
 
 		if (dx != 0)