*<Null safety>*
DoubleProperty? doubleProperty (String name)
DoubleProperty? doubleProperty(String name) { if (_writer == null) { return DoubleProperty.deleted(); } if (_properties.containsKey(name)) { if (_properties[name] is! DoubleProperty) { throw InspectStateError("Can't create DoubleProperty named $name;" ' a different type exists.'); } return _properties[name] as DoubleProperty?; } return _properties[name] = DoubleProperty._(name, this, _writer!); }