define

const (
	// PullIfMissing is one of the values that BuilderOptions.PullPolicy
	// can take, signalling that the source image should be pulled from a
	// registry if a local copy of it is not already present.
	PullIfMissing PullPolicy = iota
	// PullAlways is one of the values that BuilderOptions.PullPolicy can
	// take, signalling that a fresh, possibly updated, copy of the image
	// should be pulled from a registry before the build proceeds.
	PullAlways
	// PullIfNewer is one of the values that BuilderOptions.PullPolicy
	// can take, signalling that the source image should only be pulled
	// from a registry if a local copy is not already present or if a
	// newer version the image is present on the repository.
	PullIfNewer
	// PullNever is one of the values that BuilderOptions.PullPolicy can
	// take, signalling that the source image should not be pulled from a
	// registry if a local copy of it is not already present.
	PullNever
)