cipher-base===[](https://travis-ci.org/crypto-browserify/cipher-base)Abstract base class to inherit from if you want to create streams implementingthe same api as node crypto streams.Requires you to implement 2 methods `_final` and `_update`. `_update` takes abuffer and should return a buffer, `_final` takes no arguments and should returna buffer.The constructor takes one argument and that is a string which if present switchesit into hash mode, i.e. the object you get from crypto.createHash orcrypto.createSign, this switches the name of the final method to be the stringyou passed instead of `final` and returns `this` from update.