_TypeError(类型“List<String>”不是类型“UnmodifiableListView<String>”的子类型)

UnmodifiableListView 在提供者中?

_TypeError (type 'List<String>' is not a subtype of type 'UnmodifiableListView<String>')

这是我的密码

List<String> _failures = [
    '>1.5 year',
    '3 months to 1.5 years',
    '2 weeks to 3 months',
    '2 days to 2 weeks',
    'Now',
  ];

UnmodifiableListView<String> get failures => _failures;