AllKeys returns a list of all unique keys from all maps.

Contains returns true if the string is contained within this list.

NewTextFormat creates the default text formatter.

Unique returns a unique array of strings.

Command is a struct containing the details of an external command to be executed.

CommandError is the error object encapsulating an error from a Command.

DefaultCommandRunner the default implementation of this, will actually execute things.

TextFormat lets use a custom text format.

CommandRunner interface that wraps the RunWithoutRetry function.