getMetaWhere method Null safety

Json? getMetaWhere(
  1. Function whereFunction,
  2. [dynamic scheme]
)

Implementation

Json? getMetaWhere(Function whereFunction, [dynamic scheme]) =>
    _metaData.firstWhereOrNull((m) => (m is Json &&
        whereFunction(m) == true &&
        ((scheme != null && m.scheme == scheme) ||
            (scheme == null && m.scheme == null)))) as Json?;