@Test
public void testGetContractTxReceipt() {

  // given
  final ContractOperation mockOperation = mock(ContractOperation.class);
  when(mockOperation.getContractTxReceipt(any(ContractTxHash.class)))
      .thenReturn(ContractTxReceipt.newBuilder().build());
  final AergoClient mockClient = mock(AergoClient.class);
  when(mockClient.getContractOperation()).thenReturn(mockOperation);
  final ClientProvider mockClientProvider = mock(ClientProvider.class);
  when(mockClientProvider.getClient()).thenReturn(mockClient);
  // then
  final QueryApi queryApi = new QueryApiImpl(mockClientProvider);
  final ContractTxReceipt contractTxReceipt = queryApi.getContractTxReceipt(anyContractTxHash);
  assertNotNull(contractTxReceipt);
}