From 9a955463862d9912c5a01bfe86f1252db0ae9142 Mon Sep 17 00:00:00 2001
From: Xavier Lau <hi@xavier.zone>
Date: Sun, 14 Nov 2021 20:39:15 +0800
Subject: [PATCH] Import Missing Item

---
 frame/staking/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/staking/src/lib.rs b/frame/staking/src/lib.rs
index 930b125768..daaa7d5315 100644
--- a/frame/staking/src/lib.rs
+++ b/frame/staking/src/lib.rs
@@ -390,7 +390,7 @@ pub mod pallet {
 		offence::{Offence, OffenceDetails, OffenceError, OnOffenceHandler, ReportOffence},
 		SessionIndex,
 	};
-	use sp_std::collections::btree_map::BTreeMap;
+	use sp_std::{borrow::ToOwned, collections::btree_map::BTreeMap, prelude::*};
 	// --- darwinia-network ---
 	use crate::*;
 	use darwinia_staking_rpc_runtime_api::RuntimeDispatchInfo;