code: def _flattenBlendArgs(args):
      token_list = []
      for arg in args:
          if isinstance(arg, list):
              token_list.extend(arg)
              token_list.append("blend")
          else:
              token_list.append(arg)
      return token_list
  
imports: from fontTools.cffLib import maxStackLimit
label_desc: Use image node_id 4 for calling a global function with example usage: _flattenBlendArgs(args) and returns: token_list