Michael TsaiCovariance and Contravariance: http://mjtsai.com/blog/2015/11/29/covariance-and-contravariance/ … #mjtsaiblog
When you tweet with a location, Twitter stores that location. You can switch location on/off before each Tweet and always have the option to delete your location history. Learn more
Covariance and Contravariance: http://mjtsai.com/blog/2015/11/29/covariance-and-contravariance/ … #mjtsaiblog
