将类型param的实例与null进行比较,即使没有类约束？

if (param == null)
{
    // Handle the case where param is null
}
else
{
    // Handle the case where param is not null
}

if (param == null)
{
    // Handle the case where param is null
}
else
{
    // Handle the case where param is not null
}

if param is None:
    # Handle the case where param is null
else:
    # Handle the case where param is not null