If the traversal option MANAGE_DISTANCE_BETWEEN_STEPS prevents the bot from stepping a path, step() returns false.
The method should only return false if the next vertex could not be stepped, as an indicator that a cached path needs to be re-generated.
Yep that's why i want the return value not be a boolean, because 2 values are not enough. But cloud told me to make a thread because it should not return false.