code: def _check_stack_for_module_return(stack):
      
      fail = (
          len(stack) != 1
          or not isinstance(stack[0], instrs.LOAD_CONST)
          or stack[0].arg is not None
      )
  
      if fail:
          raise DecompilationError(
              "Reached end of non-function code "
              "block with unexpected stack: %s." % stack
          )
docs: Verify that the stack is in the expected state before the dummy
      RETURN_VALUE instruction of a module or class.