RustArc<T>.fromRaw  constructor 
      
      RustArc<T>.fromRaw ({ 
    
- required int ptr,
- required int externalSizeOnNative,
- required RustArcStaticData<T> staticData,
Mimic std::sync::Arc::from_raw
Implementation
RustArc.fromRaw({
  required int ptr,
  required super.externalSizeOnNative,
  required RustArcStaticData<T> staticData,
})  : assert(ptr != 0),
      _staticData = staticData,
      super(ptr: PlatformPointerUtil.ptrFromInt(ptr));