diff --git a/internal/epub/epub_tree.go b/internal/epub/epub_tree.go
index cac65f0..dc329ed 100644
--- a/internal/epub/epub_tree.go
+++ b/internal/epub/epub_tree.go
@@ -2,58 +2,12 @@ package epub
 
 import (
 	"path/filepath"
-	"strings"
+
+	"github.com/celogeek/go-comic-converter/v2/internal/epub/tree"
 )
 
-type Tree struct {
-	Nodes map[string]*Node
-}
-
-type Node struct {
-	Value    string
-	Children []*Node
-}
-
-func NewTree() *Tree {
-	return &Tree{map[string]*Node{
-		".": {".", []*Node{}},
-	}}
-}
-
-func (n *Tree) Root() *Node {
-	return n.Nodes["."]
-}
-
-func (n *Tree) Add(filename string) {
-	cn := n.Root()
-	cp := ""
-	for _, p := range strings.Split(filepath.Clean(filename), string(filepath.Separator)) {
-		cp = filepath.Join(cp, p)
-		if _, ok := n.Nodes[cp]; !ok {
-			n.Nodes[cp] = &Node{Value: p, Children: []*Node{}}
-			cn.Children = append(cn.Children, n.Nodes[cp])
-		}
-		cn = n.Nodes[cp]
-	}
-}
-
-func (n *Node) toString(indent string) string {
-	r := strings.Builder{}
-	if indent != "" {
-		r.WriteString(indent)
-		r.WriteString("- ")
-		r.WriteString(n.Value)
-		r.WriteString("\n")
-	}
-	indent += "  "
-	for _, c := range n.Children {
-		r.WriteString(c.toString(indent))
-	}
-	return r.String()
-}
-
 func (e *ePub) getTree(images []*Image, skip_files bool) string {
-	t := NewTree()
+	t := tree.New()
 	for _, img := range images {
 		if skip_files {
 			t.Add(img.Path)
@@ -66,5 +20,5 @@ func (e *ePub) getTree(images []*Image, skip_files bool) string {
 		c = c.Children[0]
 	}
 
-	return c.toString("")
+	return c.ToString("")
 }
diff --git a/internal/epub/tree/epub_tree.go b/internal/epub/tree/epub_tree.go
new file mode 100644
index 0000000..3b69b54
--- /dev/null
+++ b/internal/epub/tree/epub_tree.go
@@ -0,0 +1,53 @@
+package tree
+
+import (
+	"path/filepath"
+	"strings"
+)
+
+type Tree struct {
+	Nodes map[string]*Node
+}
+
+type Node struct {
+	Value    string
+	Children []*Node
+}
+
+func New() *Tree {
+	return &Tree{map[string]*Node{
+		".": {".", []*Node{}},
+	}}
+}
+
+func (n *Tree) Root() *Node {
+	return n.Nodes["."]
+}
+
+func (n *Tree) Add(filename string) {
+	cn := n.Root()
+	cp := ""
+	for _, p := range strings.Split(filepath.Clean(filename), string(filepath.Separator)) {
+		cp = filepath.Join(cp, p)
+		if _, ok := n.Nodes[cp]; !ok {
+			n.Nodes[cp] = &Node{Value: p, Children: []*Node{}}
+			cn.Children = append(cn.Children, n.Nodes[cp])
+		}
+		cn = n.Nodes[cp]
+	}
+}
+
+func (n *Node) ToString(indent string) string {
+	r := strings.Builder{}
+	if indent != "" {
+		r.WriteString(indent)
+		r.WriteString("- ")
+		r.WriteString(n.Value)
+		r.WriteString("\n")
+	}
+	indent += "  "
+	for _, c := range n.Children {
+		r.WriteString(c.ToString(indent))
+	}
+	return r.String()
+}