public async void ByTenantIdOwnerIdEnvironmentIdVariableTemplateId_Not_Exists()
        {
            var mock = new ServiceMockFacade <ITenantVariableRepository>();

            mock.RepositoryMock.Setup(x => x.ByTenantIdOwnerIdEnvironmentIdVariableTemplateId(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>())).Returns(Task.FromResult <TenantVariable>(null));
            var service = new TenantVariableService(mock.LoggerMock.Object,
                                                    mock.RepositoryMock.Object,
                                                    mock.ModelValidatorMockFactory.TenantVariableModelValidatorMock.Object,
                                                    mock.BOLMapperMockFactory.BOLTenantVariableMapperMock,
                                                    mock.DALMapperMockFactory.DALTenantVariableMapperMock);

            ApiTenantVariableResponseModel response = await service.ByTenantIdOwnerIdEnvironmentIdVariableTemplateId(default(string), default(string), default(string), default(string));

            response.Should().BeNull();
            mock.RepositoryMock.Verify(x => x.ByTenantIdOwnerIdEnvironmentIdVariableTemplateId(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>()));
        }