bag := multistep.BasicStateBag{}
bag.Put("key", "value")
s := bag.Get("key")
if bag.Has("key") { // do something }The `BasicStateBag` type is used in many of the other types provided by the `multistep` package, including `StepState`, which is used to manage the state of a particular step in a multi-step process. Overall, the `github.com/mitchellh/multistep` package is a useful library for building complex workflows in Go, and the `BasicStateBag` type is an important component for managing state across multiple steps.