From 7571090eb0a6a93e9fd3eaf0003c53097019f7ef Mon Sep 17 00:00:00 2001
From: Hong Minhee <hong.minhee@gmail.com>
Date: Fri, 8 Mar 2019 00:57:58 +0900
Subject: [PATCH] Address.Size constant

---
 CHANGES.md           |  1 +
 Libplanet/Address.cs | 12 +++++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index e2d08d34aba..e7263ce90dd 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -30,6 +30,7 @@ To be released.
     [[#120], [#123] by Yang Chun Ung, [#126], [#127]]
  -  `Address` and `TxId` are now serializable.
     [[#99], [#124] by Qria]
+ -  Added `Address.Size` constant, which is fixed to the `Int32` 20.
  -  `Swarm.AddPeersAsync()` was fixed so that unreachable `Peer`s are ignored.
     [[#128]]
 
diff --git a/Libplanet/Address.cs b/Libplanet/Address.cs
index a8679b9a557..f61cbed1808 100644
--- a/Libplanet/Address.cs
+++ b/Libplanet/Address.cs
@@ -43,6 +43,12 @@ namespace Libplanet
     public partial struct Address : ISerializable
     #pragma warning restore CS0282
     {
+        /// <summary>
+        /// The <see cref="byte"/>s size that each <see cref="Address"/> takes.
+        /// <para>It is 20 <see cref="byte"/>s.</para>
+        /// </summary>
+        public const int Size = 20;
+
         private ImmutableArray<byte> _byteArray;
 
         /// <summary>
@@ -67,7 +73,7 @@ public Address(byte[] address)
                 throw new NullReferenceException("address must not be null");
             }
 
-            if (address.Length != 20)
+            if (address.Length != Size)
             {
                 throw new ArgumentException("address must be 20 bytes");
             }
@@ -142,7 +148,7 @@ public ImmutableArray<byte> ByteArray
             {
                 if (_byteArray.IsDefault)
                 {
-                    _byteArray = new byte[20].ToImmutableArray();
+                    _byteArray = new byte[Size].ToImmutableArray();
                 }
 
                 return _byteArray;
@@ -245,7 +251,7 @@ private static byte[] DeriveAddress(PublicKey key)
             byte[] hashPayload = key.Format(false).Skip(1).ToArray();
             var output = CalculateHash(hashPayload);
 
-            return output.Skip(output.Length - 20).ToArray();
+            return output.Skip(output.Length - Size).ToArray();
         }
 
         private static byte[] DeriveAddress(string hex)