[0.0.1] - 09/10/2020. [0.0.3] adding example [0.0.4] -09/10/2020 [0.0.5] -09/10/2020 [0.0.6] -28/10/2020 [0.0.7] -01/11/2020 [0.0.8] -22/1/2020 [1.0.0] -12/09/2023 migrate to null saftey