ChangeWorkingDir to the directory, and return a function which restores the previous working directory.

Patch changes the value of an environment variable, and returns a function which will reset the the value of that variable back to the previous state.

PatchAll sets the environment to env, and returns a function which will reset the environment back to the previous state.

ToMap takes a list of strings in the format returned by [os.Environ] and returns a mapping of keys to values.