<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _check_stack_for_module_return(stack):
 """ Verify that the stack is in the expected state before the dummy RETURN_VALUE instruction of a module or class. """

    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
        )