Expose interface instead of implementation detail struct

trans/trans.go

@@ -7,6 +7,9 @@ import (
 	"log"
 )
 
+type Translator interface {
+	Translate() []string
+}
 
 type transJob struct {
 	word string
@@ -14,7 +17,7 @@ type transJob struct {
 	toLang string
 }
 
-func New(word, fromLang, toLang string) transJob {
+func New(word, fromLang, toLang string) Translator {
 	return transJob{word: word, fromLang: fromLang, toLang: toLang}
 }