diff --git a/dorkgen.go b/dorkgen.go
index d2e5c44..03ae1c0 100644
--- a/dorkgen.go
+++ b/dorkgen.go
@@ -1,17 +1,15 @@
 package dorkgen
 
-// engineFactory is the main interface for
+// EngineFactory is the main interface for
 // search engine implementations.
-type engineFactory interface {
-	Site(string) *GoogleSearch
-	ToString() string
-	ToURL() string
-	Intext(string) *GoogleSearch
-	Inurl(string) *GoogleSearch
-	Filetype(string) *GoogleSearch
-	Cache(string) *GoogleSearch
-	Related(string) *GoogleSearch
-	Ext(string) *GoogleSearch
-	Exclude(string) *GoogleSearch
-	Group(string) *GoogleSearch
+type EngineFactory struct {
+	tags []string
+}
+
+func (e *EngineFactory) concat(tag string, value string, quotes bool) string {
+	if quotes {
+		return tag + "\"" + value + "\""
+	}
+
+	return tag + value
 }
diff --git a/google.go b/google.go
index 9264deb..d2d6b54 100644
--- a/google.go
+++ b/google.go
@@ -18,18 +18,9 @@ const (
 	intextTag   = "intext:"
 )
 
-// GoogleSearch is the Google implementation for Dorkgen
+// GoogleSearch is the Google search implementation for Dorkgen
 type GoogleSearch struct {
-	engineFactory
-	tags []string
-}
-
-func concat(tag string, value string, quotes bool) string {
-	if quotes {
-		return tag + "\"" + value + "\""
-	}
-
-	return tag + value
+	EngineFactory
 }
 
 // ToString converts all tags to a single request
@@ -53,8 +44,7 @@ func (e *GoogleSearch) ToURL() string {
 
 // Site specifically searches that particular site and lists all the results for that site.
 func (e *GoogleSearch) Site(site string) *GoogleSearch {
-	e.tags = append(e.tags, concat(siteTag, site, false))
-
+	e.tags = append(e.tags, e.concat(siteTag, site, false))
 	return e
 }
 
@@ -66,43 +56,43 @@ func (e *GoogleSearch) Or() *GoogleSearch {
 
 // Intext searches for the occurrences of keywords all at once or one at a time.
 func (e *GoogleSearch) Intext(text string) *GoogleSearch {
-	e.tags = append(e.tags, concat(intextTag, text, true))
+	e.tags = append(e.tags, e.concat(intextTag, text, true))
 	return e
 }
 
 // Inurl searches for a URL matching one of the keywords.
 func (e *GoogleSearch) Inurl(url string) *GoogleSearch {
-	e.tags = append(e.tags, concat(urlTag, url, true))
+	e.tags = append(e.tags, e.concat(urlTag, url, true))
 	return e
 }
 
 // Filetype searches for a particular filetype mentioned in the query.
 func (e *GoogleSearch) Filetype(filetype string) *GoogleSearch {
-	e.tags = append(e.tags, concat(filetypeTag, filetype, true))
+	e.tags = append(e.tags, e.concat(filetypeTag, filetype, true))
 	return e
 }
 
 // Cache shows the version of the web page that Google has in its cache.
 func (e *GoogleSearch) Cache(url string) *GoogleSearch {
-	e.tags = append(e.tags, concat(cacheTag, url, true))
+	e.tags = append(e.tags, e.concat(cacheTag, url, true))
 	return e
 }
 
 // Related list web pages that are “similar” to a specified web page.
 func (e *GoogleSearch) Related(url string) *GoogleSearch {
-	e.tags = append(e.tags, concat(relatedTag, url, true))
+	e.tags = append(e.tags, e.concat(relatedTag, url, true))
 	return e
 }
 
 // Ext searches for a particular file extension mentioned in the query.
 func (e *GoogleSearch) Ext(ext string) *GoogleSearch {
-	e.tags = append(e.tags, concat(extTag, ext, false))
+	e.tags = append(e.tags, e.concat(extTag, ext, false))
 	return e
 }
 
 // Exclude excludes some results.
 func (e *GoogleSearch) Exclude(value string) *GoogleSearch {
-	e.tags = append(e.tags, concat(excludeTag, value, false))
+	e.tags = append(e.tags, e.concat(excludeTag, value, false))
 	return e
 }
 
@@ -114,6 +104,6 @@ func (e *GoogleSearch) Group(value string) *GoogleSearch {
 
 // Intitle searches for occurrences of keywords in title all or one.
 func (e *GoogleSearch) Intitle(value string) *GoogleSearch {
-	e.tags = append(e.tags, concat(intitleTag, value, true))
+	e.tags = append(e.tags, e.concat(intitleTag, value, true))
 	return e
 }