@Test
public void testInterceptorIsCalled() throws Exception {

  MethodDescriptor descriptor = BigtableGrpc.getMutateRowMethod();
  ChannelPool pool = new ChannelPool(new MockChannelFactory(), 1);
  ClientCall call = pool.newCall(descriptor, CallOptions.DEFAULT);
  Metadata headers = new Metadata();
  call.start(null, headers);
}