fixes

Author: GueLaKais

rosidl_runtime_rs/src/sequence.rs

@@ -455,7 +455,7 @@ where
 /// ```
 /// use rosidl_runtime_rs::Sequence;
 ///
-/// let original = Sequence::new(6);
+/// let original: Sequence<u64> = Sequence::new(6);
 /// let cloned = original.clone();
 ///
 /// ```