code: def force_list(x):
      if isinstance(x, tuple):
          return list(x)
      elif not isinstance(x, list):
          return [x]
      return x
  
file_path: nnabla/python/src/nnabla/backward_function/utils.py
imports: import nnabla.functions
label_desc: Use image node_id 4 for calling a global function with example usage: force_list(x) and returns: x, list, list