Compare raw-value.

src/types/document.rs

@@ -74,3 +74,15 @@ impl<'s> StandardProperties<'s> for Heading<'s> {
         self.source
     }
 }
+
+impl<'s> Heading<'s> {
+    pub fn get_raw_value(&self) -> String {
+        // TODO: I think this could just return a string slice instead of an owned string.
+        let title_source: String = self
+            .title
+            .iter()
+            .map(|obj| obj.get_standard_properties().get_source())
+            .collect();
+        title_source
+    }
+}