Bool returns the boolean state associated with the given value, or the value "def", if the value is blank.

EnvironmentOf creates a new `Environment` initialized with the givne `Fetcher`, "f".

Int returns the int value associated with the given value, or the value "def", if the value is blank.

NewFrom returns a new `*config.Configuration` that reads both its Git and Environment-level values from the ones provided instead of the actual `.gitconfig` file or `os.Getenv`, respectively.

NewOsFetcher returns a new *OsFetcher.

SortExtensions sorts a map of extensions in ascending order by Priority.

An Extension describes how to manipulate files during smudge and clean.

OsFetcher is an implementation of the Fetcher type for communicating with the system's environment.

Values is a convenience type used to call the NewFromValues function.

An Environment adds additional behavior to a Fetcher, such a type conversion, and default values.

Fetcher provides an interface to get typed information out of a configuration "source".