code: def get_scala_classes(scala_nn_root):
      raw_result = [
          extract_scala_class(join(scala_nn_root, name))
          for name in os.listdir(scala_nn_root)
          if isfile(join(scala_nn_root, name))
      ]  # noqa
      return set(
          class_name
          for class_name in raw_result
          if class_name is not None
      )
  
imports: import os
  import re
  from os.path import isfile, join
label_desc: Use image node_id 2 for calling a global function with example usage: get_scala_classes(scala_nn_root) and returns: set