public void Should_SetValue_ForStandardInput() { //arrange int dimensions = 2; double newValue = 5; IJsonSerializationProvider jsonSerializationProvider = A.Fake <IJsonSerializationProvider>(); IMatrixProvider matrixProvider = new MatrixProvider(jsonSerializationProvider, dimensions); matrixProvider.SetValue(0, 0, newValue); //act double actualOutput = matrixProvider.GetValue(0, 0); //assert actualOutput.Should().Be(newValue); }