supply

type Command interface {
	Execute(string, io.Writer, io.Writer, string, ...string) error
	Output(dir string, program string, args ...string) (string, error)
}

type Installer interface {
	InstallDependency(libbuildpack.Dependency, string) error
	InstallOnlyVersion(string, string) error
}

type Manifest interface {
	AllDependencyVersions(string) []string
	DefaultVersion(string) (libbuildpack.Dependency, error)
	IsCached() bool
}

type Stager interface {
	BuildDir() string
	CacheDir() string
	DepDir() string
	DepsIdx() string
	LinkDirectoryInDepDir(string, string) error
	WriteEnvFile(string, string) error
	WriteProfileD(string, string) error
}

type Supplier struct {
	PythonVersion string
	Manifest      Manifest
	Installer     Installer
	Stager        Stager
	Command       Command
	Log           *libbuildpack.Logger
	Logfile       *os.File
	HasNltkData   bool
}