@Test
public void testGetServerInfo() {

  // given
  final BlockchainOperation mockOperation = mock(BlockchainOperation.class);
  when(mockOperation.getServerInfo(ArgumentMatchers.<String>anyList()))
      .thenReturn(ServerInfo.newBuilder().build());
  final AergoClient mockClient = mock(AergoClient.class);
  when(mockClient.getBlockchainOperation()).thenReturn(mockOperation);
  final ClientProvider mockClientProvider = mock(ClientProvider.class);
  when(mockClientProvider.getClient()).thenReturn(mockClient);
  // then
  final QueryApi queryApi = new QueryApiImpl(mockClientProvider);
  final ServerInfo serverInfo = queryApi.getServerInfo(Collections.<String>emptyList());
  assertNotNull(serverInfo);
}