test stable ordering with pagination (#2683)

src/schema/document/mod.rs

@@ -41,6 +41,7 @@
 //! use tantivy::schema::document::{DeserializeError, DocumentDeserialize, DocumentDeserializer};
 //!
 //! /// Our custom document to let us use a map of `serde_json::Values`.
+//! #[allow(dead_code)]
 //! pub struct MyCustomDocument {
 //!     // Tantivy provides trait implementations for common `serde_json` types.
 //!     fields: BTreeMap<Field, serde_json::Value>