RemoteGrpcPortReadOperation extends Operation { @Override public boolean supportsRestart() { return true; } RemoteGrpcPortReadOperation(
      FnDataService beamFnDataService,
      String ptransformId,
      IdGenerator bundleIdSupplier,
      Coder<WindowedValue<T>> coder,
      OutputReceiver[] receivers,
      OperationContext context); @Override void start(); @Override void finish(); @Override void abort(); @Override boolean supportsRestart(); @Override String toString();  }
@Test public void testSupportsRestart() { assertTrue(operation.supportsRestart()); }