def rotate_ports(self):
for port in self.ports:<EOL><INDENT>port.tile_id = ((port.tile_id + <NUM_LIT:1>) % len(hexgrid.coastal_tile_ids())) + <NUM_LIT:1><EOL>port.direction = hexgrid.rotate_direction(hexgrid.EDGE, port.direction, ccw=True)<EOL><DEDENT>self.notify_observers()<EOL>
Rotates the ports 90 degrees. Useful when using the default port setup but the spectator is watching
at a "rotated" angle from "true north".