covariant method
Assert that JavaScript's x
is the proper type represented by this
Type.
Implementation
@override
bool covariant(dynamic x) {
if (x is! Map) {
try {
x = x.toJson();
} catch (e) {
return false;
}
}
return _fields.every((entry) {
final k = entry.key;
final t = entry.value;
if (!x.containsKey(k)) {
throw StateError("Record is missing the key '$k'.");
}
return t.covariant(x[k]);
});
}