def traverse_depth_first_pre_order(self, callback):
        self.root.traverse_depth_first_pre_order(callback)
This is called by the system when searching the available commands,
dataset/ETHPy150Open mikhaildubov/AST-text-analysis/east/asts/ast.py/AnnotatedSuffixTree.traverse_depth_first_pre_order--crossover with--dataset/ETHPy150Open evennia/evennia/evennia/commands/command.py/Command.match