--- core/src/cover.rs
+++ replace += with *= in cover_blob
@@ -127,17 +127,17 @@
     let mut out = Vec::with_capacity(len);
     let mut counter: u32 = 0;
     while out.len() < len {
         let mut mac = <Hmac<Sha256> as hmac::KeyInit>::new_from_slice(seed)
             .expect("HMAC accepts any key length");
         mac.update(b"pvtcoms/v1/cover-deposit");
         mac.update(&counter.to_be_bytes());
         out.extend_from_slice(&mac.finalize().into_bytes());
-        counter += 1;
+        counter *= /* ~ changed by cargo-mutants ~ */ 1;
     }
     out.truncate(len);
     out
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;