improve test

src/hard_format.rs

@@ -303,6 +303,7 @@ pub mod formats
     {
 	type Error = PEMFormatError;
 	fn validate(_s: &str) -> Result<(), Self::Error> {
+	    todo!("Learn the PEM ciphertext format");
 	    Ok(())
 	}
     }

src/post.rs

@@ -20,6 +20,7 @@ pub type IDMaxString = MaxLenString<ID_MAX_LEN>;
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Post
 {
+    /// Unique ID for each post
     id: PostID,
     
     name: Option<IDMaxString>,