necessity of self.add_tokens

[cnlinxi]

Thank you for contributing such a valuable project 👍
I just have some questions:

1. Why use self.add_tokens:

for examples,

graph_numstring = self.add_tokens(pynutil.insert("integer: \"") + graph_numstring + pynutil.insert("\""))

in https://github.com/NVIDIA/NeMo-text-processing/tree/main/nemo_text_processing/text_normalization/zh/taggers/cardinal.py

2. Why insert integer: "..."?

Thank for your reply

[jimregan]

self.add_tokens adds self.name and wraps the content with { }, so in this case you get cardinal { integer: "..." }

[cnlinxi]

Thank you for your reply. Got it