diff --git a/Cargo.toml b/Cargo.toml
index 468667ca..aa09147f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "finality-grandpa"
-version = "0.7.0"
+version = "0.7.1"
 description = "PBFT-based finality gadget for blockchains"
 authors = ["Parity Technologies <admin@parity.io>"]
 license = "GPL-3.0"
diff --git a/src/lib.rs b/src/lib.rs
index dcdf2f31..ae634348 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -345,6 +345,35 @@ pub struct CommitValidationResult<H, N> {
 	num_invalid_voters: usize,
 }
 
+impl<H, N> CommitValidationResult<H, N> {
+	/// Returns the commit GHOST i.e. the block with highest number for which
+	/// the cumulative votes of descendents and itself reach finalization
+	/// threshold.
+	pub fn ghost(&self) -> Option<&(H, N)> {
+		self.ghost.as_ref()
+	}
+
+	/// Returns the number of precommits in the commit.
+	pub fn num_precommits(&self) -> usize {
+		self.num_precommits
+	}
+
+	/// Returns the number of duplicate precommits in the commit.
+	pub fn num_duplicated_precommits(&self) -> usize {
+		self.num_duplicated_precommits
+	}
+
+	/// Returns the number of equivocated precommits in the commit.
+	pub fn num_equivocations(&self) -> usize {
+		self.num_equivocations
+	}
+
+	/// Returns the number of invalid voters in the commit.
+	pub fn num_invalid_voters(&self) -> usize {
+		self.num_invalid_voters
+	}
+}
+
 impl<H, N> Default for CommitValidationResult<H, N> {
 	fn default() -> Self {
 		CommitValidationResult {
@@ -407,7 +436,7 @@ pub fn validate_commit<H, N, S, I, C: Chain<H, N>>(
 				validation_result.num_equivocations += 1;
 				// allow only one equivocation per voter, as extras are redundant.
 				if !equivocated.insert(id) {
-					return Ok(validation_result) 
+					return Ok(validation_result)
 				}
 			},
 			ImportResult { duplicated, valid_voter, .. } => {
diff --git a/src/voter/mod.rs b/src/voter/mod.rs
index 0a07185c..04a61c46 100644
--- a/src/voter/mod.rs
+++ b/src/voter/mod.rs
@@ -118,19 +118,15 @@ pub trait Environment<H: Eq, N: BlockNumberOps>: Chain<H, N> {
 
 /// Communication between nodes that is not round-localized.
 #[derive(Debug, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "derive-codec", derive(Encode, Decode))]
 pub enum CommunicationOut<H, N, S, Id> {
 	/// A commit message.
-	#[cfg_attr(feature = "derive-codec", codec(index = "0"))]
 	Commit(u64, Commit<H, N, S, Id>),
 	/// Auxiliary messages out.
-	#[cfg_attr(feature = "derive-codec", codec(index = "1"))]
 	Auxiliary(AuxiliaryCommunication<H, N, Id>),
 }
 
 /// The outcome of processing a commit.
 #[derive(Debug, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "derive-codec", derive(Encode, Decode))]
 pub enum CommitProcessingOutcome {
 	/// It was beneficial to process this commit.
 	Good(GoodCommit),
@@ -140,7 +136,6 @@ pub enum CommitProcessingOutcome {
 
 /// The result of processing for a good commit.
 #[derive(Debug, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "derive-codec", derive(Encode, Decode))]
 pub struct GoodCommit {
 	_priv: (), // lets us add stuff without breaking API.
 }
@@ -153,7 +148,6 @@ impl GoodCommit {
 
 /// The result of processing for a bad commit
 #[derive(Debug, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "derive-codec", derive(Encode, Decode))]
 pub struct BadCommit {
 	_priv: (), // lets us add stuff without breaking API.
 	num_precommits: usize,
@@ -197,7 +191,6 @@ impl<H, N> From<CommitValidationResult<H, N>> for BadCommit {
 }
 
 /// Callback used to propagate the commit in case the outcome is good.
-#[cfg_attr(feature = "derive-codec", derive(Encode, Decode))]
 pub enum Callback {
 	/// Default value.
 	Blank,
@@ -205,6 +198,7 @@ pub enum Callback {
 	Work(Box<FnMut(CommitProcessingOutcome) + Send>),
 }
 
+#[cfg(test)]
 impl Clone for Callback {
 	fn clone(&self) -> Self {
 		Callback::Blank
@@ -221,14 +215,11 @@ impl Callback {
 }
 
 /// Communication between nodes that is not round-localized.
-#[derive(Clone)]
-#[cfg_attr(feature = "derive-codec", derive(Encode, Decode))]
+#[cfg_attr(test, derive(Clone))]
 pub enum CommunicationIn<H, N, S, Id> {
 	/// A commit message.
-	#[cfg_attr(feature = "derive-codec", codec(index = "0"))]
 	Commit(u64, CompactCommit<H, N, S, Id>, Callback),
 	/// Auxiliary messages out.
-	#[cfg_attr(feature = "derive-codec", codec(index = "1"))]
 	Auxiliary(AuxiliaryCommunication<H, N, Id>),
 }
 
diff --git a/src/voter/voter_state.rs b/src/voter/voter_state.rs
deleted file mode 100644
index 33dcb6bf..00000000
--- a/src/voter/voter_state.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
-// This file is part of finality-grandpa.
-
-// finality-grandpa is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// finality-grandpa is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with finality-grandpa. If not, see <http://www.gnu.org/licenses/>.
-
-//! Exposed voter-state.
-
-use std::sync::Arc;
-use parking_lot::RwLock;
-
-///
-pub struct VoterState {
-	inner: Arc<RwLock<Inner>>,
-}
-
-pub(super) struct Inner {
-
-}