Compare value for export block.

src/types/lesser_element.rs

@@ -65,7 +65,7 @@ pub struct ExportBlock<'s> {
     pub source: &'s str,
     pub name: Option<&'s str>,
     pub data: Option<&'s str>,
-    pub contents: &'s str,
+    pub contents: String,
 }
 
 #[derive(Debug)]