DartDart_HeapSamplingCreateCallbackFunction typedef
        DartDart_HeapSamplingCreateCallbackFunction =
     Pointer<Void>  Function(Dart_Isolate isolate, Dart_IsolateGroup isolate_group, Pointer<Char>  cls_name, int allocation_size)
    
    
    
Implementation
typedef DartDart_HeapSamplingCreateCallbackFunction
    = ffi.Pointer<ffi.Void> Function(
        Dart_Isolate isolate,
        Dart_IsolateGroup isolate_group,
        ffi.Pointer<ffi.Char> cls_name,
        int allocation_size);