diff --git a/components/document/transformer/splitter/markdown/header.go b/components/document/transformer/splitter/markdown/header.go
index 52b196d..6d46840 100644
--- a/components/document/transformer/splitter/markdown/header.go
+++ b/components/document/transformer/splitter/markdown/header.go
@@ -29,25 +29,25 @@ type HeaderConfig struct {
 	// Headers specify the headers to be identified and their names in document metadata.
 	// Headers can only consist of '#'.
 	// e.g.
-	//	 // the Header Config:
-	//   config := &HeaderConfig{
-	//   	Headers: map[string]string{ "##": "headerNameOfLevel2" },
+	// 	// the Header Config:
+	// 	config := &HeaderConfig{
+	// 		Headers: map[string]string{ "##": "headerNameOfLevel2" },
 	// 		TrimHeaders: false,
-	//   }
+	// 	}
 	//
-	//	 // the original document:
-	//	 originDoc := &schema.Document{
-	//   	Content: "hell\n##Title 2\n hello world",
-	//   }
+	// 	// the original document:
+	// 	originDoc := &schema.Document{
+	// 		Content: "hell\n##Title 2\n hello world",
+	// 	}
 	//
-	//	 // one of the split documents:
-	//   splitDoc := &schema.Document{
-	//		Content: "##Title 2\n hello world",
+	// 	// one of the split documents:
+	// 	splitDoc := &schema.Document{
+	// 		Content: "##Title 2\n hello world",
 	// 		Metadata: map[string]any{
-	//			// other fields
+	// 			// other fields
 	// 			"headerNameOfLevel2": "Title 2",
 	// 		},
-	//   }
+	// 	}
 	Headers map[string]string
 	// TrimHeaders specify if results contain header lines.
 	TrimHeaders bool