'This implements the actual traversal. The traverse lock has
already been checked (in the Exit command) at this point.
Args:
traversing_object (Object): Object traversing us.
target_location (Object): Where target is going.'

def at_traverse(self, traversing_object, target_location):

    source_location = traversing_object.location
    if traversing_object.move_to(target_location):
        self.at_after_traverse(traversing_object, source_location)
    elif self.db.err_traverse:
        self.caller.msg(self.db.err_traverse)
    else:
        self.at_failed_traverse(traversing_object)
