The code for this section is located in navigation_bot_07 part of an archive. Note that archive includes some additional folders, like maps and worlds, that are used by all projects and therefore are located outside of them. Note also that we use ROS2 Galactic now.
Sometimes we need our robot to NOT enter certain areas. Maybe we do not want it to fall in the swimming pool. Or maybe it shouldn't be anywhere close to a highway. Or we do not want our delivery bot to repeat the recent epic fail of an Anazon delivery bot that moved right across the (properly marked by police) crime scene.
Also, we might want our robot to stay within the prefered lanes, which is just opposed to staying away from keepout zones.
Finally, keep in mind that keepout zones can be different for different robots, though we are not going to explore it in this section.