code: def convert_function_name(out):
      if len(out) < 6:
          return out.lower()
      else:
          # Temporary workaround.
          # Function name fields in functions.rst should take a snake case name
          # optionally.
          out = out.replace("ReLU", "_relu")
          return (
              (
                  "".join(
                      [
                          "_" + x.lower()
                          if i < len(out) - 1
                          and x.isupper()
                          and out[i + 1].islower()
                          else x.lower() + "_"
                          if i < len(out) - 1
                          and x.islower()
                          and out[i + 1].isupper()
                          else x.lower()
                          for i, x in enumerate(list(out))
                      ]
                  )
              )
              .lstrip("_")
              .replace("__", "_")
          )
  
file_path: nnabla/build-tools/code_generator/utils/load_function_rst.py
imports: import collections
  import re
  import os
label_desc: Use image node_id 1 for calling a global function with example usage: convert_function_name(out) and returns: out, str