The base plugin used to create Appium 2.0 plugins
Wrapper around is-valid-instance and is-registered for validating `base` plugins. Returns true if app
is a valid instance of base and a plugin is not registered yet.
base-methods plugin that adds a config
method for mapping declarative configuration values to other 'base' methods or custom functions.
Util for Base that optionally prevents a plugin from being registered more than once on an instance