func NewProgram(uid, name, command, prev, v string) *Program {
	return &Program{
		id:       -1,
		uid:      uid,
		previous: prev,
		name:     name,
		command:  command,
		version:  v,
	}
}
NewProgram returns a Program with the given unique ID, name, command,
previous program ID in the pipeline and version.
package sam
import (
	"bytes"
	"errors"
	"fmt"
)
type Program struct {
	owner     *Header
	id        int32
	uid       string
	previous  string
	name      string
	command   string
	version   string
	otherTags []tagPair
}