diff --git a/X10D/src/ListExtensions/ListOfByteExtensions.cs b/X10D/src/ListExtensions/ListOfByteExtensions.cs
index 4f5f474..1fea2f8 100644
--- a/X10D/src/ListExtensions/ListOfByteExtensions.cs
+++ b/X10D/src/ListExtensions/ListOfByteExtensions.cs
@@ -22,7 +22,11 @@ namespace X10D.ListExtensions
         /// <exception cref="ArgumentNullException"><paramref name="source" /> is <see langword="null" />.</exception>
         public static string AsString(this IReadOnlyList<byte> source)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToString(source.ToArray());
         }
 
@@ -49,7 +53,11 @@ namespace X10D.ListExtensions
         /// <exception cref="ArgumentNullException"><paramref name="source" /> is <see langword="null" />.</exception>
         public static double ToDouble(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToDouble(source.ToArray(), startIndex);
         }
 
@@ -73,7 +81,11 @@ namespace X10D.ListExtensions
         /// <exception cref="ArgumentNullException"><paramref name="source" /> is <see langword="null" />.</exception>
         public static short ToInt16(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToInt16(source.ToArray(), startIndex);
         }
 
@@ -97,7 +109,11 @@ namespace X10D.ListExtensions
         /// <exception cref="ArgumentNullException"><paramref name="source" /> is <see langword="null" />.</exception>
         public static int ToInt32(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToInt32(source.ToArray(), startIndex);
         }
 
@@ -121,7 +137,11 @@ namespace X10D.ListExtensions
         /// <exception cref="ArgumentNullException"><paramref name="source" /> is <see langword="null" />.</exception>
         public static long ToInt64(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToInt64(source.ToArray(), startIndex);
         }
 
@@ -148,7 +168,11 @@ namespace X10D.ListExtensions
         /// <exception cref="ArgumentNullException"><paramref name="source" /> is <see langword="null" />.</exception>
         public static float ToSingle(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToSingle(source.ToArray(), startIndex);
         }
 
@@ -165,8 +189,15 @@ namespace X10D.ListExtensions
         /// </exception>
         public static string ToString(this IReadOnlyList<byte> source, Encoding encoding)
         {
-            Validate.IsNotNull(source, nameof(source));
-            Validate.IsNotNull(encoding, nameof(encoding));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
+            if (encoding is null)
+            {
+                throw new ArgumentNullException(nameof(encoding));
+            }
 
             return encoding.GetString(source.ToArray());
         }
@@ -193,7 +224,11 @@ namespace X10D.ListExtensions
         [CLSCompliant(false)]
         public static ushort ToUInt16(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToUInt16(source.ToArray(), startIndex);
         }
 
@@ -219,7 +254,11 @@ namespace X10D.ListExtensions
         [CLSCompliant(false)]
         public static uint ToUInt32(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToUInt32(source.ToArray(), startIndex);
         }
 
@@ -245,7 +284,11 @@ namespace X10D.ListExtensions
         [CLSCompliant(false)]
         public static ulong ToUInt64(this IReadOnlyList<byte> source, int startIndex)
         {
-            Validate.IsNotNull(source, nameof(source));
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
             return BitConverter.ToUInt64(source.ToArray(), startIndex);
         }
     }
diff --git a/X10D/src/StreamExtensions/StreamExtensions.cs b/X10D/src/StreamExtensions/StreamExtensions.cs
index 6c2a7c8..996ca1e 100644
--- a/X10D/src/StreamExtensions/StreamExtensions.cs
+++ b/X10D/src/StreamExtensions/StreamExtensions.cs
@@ -76,8 +76,15 @@ namespace X10D.StreamExtensions
         /// <returns>A decimal value read from the stream.</returns>
         public static decimal ReadDecimal(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
             const int decimalSize = sizeof(decimal);
             const int int32Size = sizeof(int);
@@ -112,8 +119,15 @@ namespace X10D.StreamExtensions
         /// <returns>A double-precision floating point value read from the stream.</returns>
         public static double ReadDouble(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -148,8 +162,15 @@ namespace X10D.StreamExtensions
         /// <returns>An two-byte unsigned integer read from the stream.</returns>
         public static short ReadInt16(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -184,8 +205,15 @@ namespace X10D.StreamExtensions
         /// <returns>An four-byte unsigned integer read from the stream.</returns>
         public static int ReadInt32(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -220,8 +248,15 @@ namespace X10D.StreamExtensions
         /// <returns>An eight-byte unsigned integer read from the stream.</returns>
         public static long ReadInt64(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -256,8 +291,15 @@ namespace X10D.StreamExtensions
         /// <returns>A single-precision floating point value read from the stream.</returns>
         public static double ReadSingle(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -294,8 +336,15 @@ namespace X10D.StreamExtensions
         [CLSCompliant(false)]
         public static ushort ReadUInt16(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -332,8 +381,15 @@ namespace X10D.StreamExtensions
         [CLSCompliant(false)]
         public static uint ReadUInt32(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -370,8 +426,15 @@ namespace X10D.StreamExtensions
         [CLSCompliant(false)]
         public static ulong ReadUInt64(this Stream stream, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -408,8 +471,15 @@ namespace X10D.StreamExtensions
         /// <returns>The number of bytes written to the stream.</returns>
         public static int Write(this Stream stream, short value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(short)];
@@ -452,8 +522,15 @@ namespace X10D.StreamExtensions
         /// <returns>The number of bytes written to the stream.</returns>
         public static int Write(this Stream stream, int value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(int)];
@@ -496,8 +573,15 @@ namespace X10D.StreamExtensions
         /// <returns>The number of bytes written to the stream.</returns>
         public static int Write(this Stream stream, long value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(long)];
@@ -542,8 +626,15 @@ namespace X10D.StreamExtensions
         [CLSCompliant(false)]
         public static int Write(this Stream stream, ushort value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(ushort)];
@@ -588,8 +679,15 @@ namespace X10D.StreamExtensions
         [CLSCompliant(false)]
         public static int Write(this Stream stream, uint value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(uint)];
@@ -634,8 +732,15 @@ namespace X10D.StreamExtensions
         [CLSCompliant(false)]
         public static int Write(this Stream stream, ulong value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(ulong)];
@@ -666,8 +771,15 @@ namespace X10D.StreamExtensions
         /// <returns>The number of bytes written to the stream.</returns>
         public static int Write(this Stream stream, float value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(float)];
@@ -698,8 +810,15 @@ namespace X10D.StreamExtensions
         /// <returns>The number of bytes written to the stream.</returns>
         public static int Write(this Stream stream, double value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
 #if NET5_0
             Span<byte> buffer = stackalloc byte[sizeof(double)];
@@ -730,8 +849,15 @@ namespace X10D.StreamExtensions
         /// <returns>The number of bytes written to the stream.</returns>
         public static int Write(this Stream stream, decimal value, Endianness endianness)
         {
-            Validate.IsNotNull(stream, nameof(stream));
-            Validate.IsDefined(endianness, nameof(endianness));
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            if (!Enum.IsDefined(typeof(Endianness), endianness))
+            {
+                throw new ArgumentOutOfRangeException(nameof(endianness));
+            }
 
             var bits = decimal.GetBits(value);
             var preWritePosition = stream.Position;
diff --git a/X10D/src/Validate.cs b/X10D/src/Validate.cs
deleted file mode 100644
index b46e88a..0000000
--- a/X10D/src/Validate.cs
+++ /dev/null
@@ -1,24 +0,0 @@
-using System;
-
-namespace X10D
-{
-    internal static class Validate
-    {
-        public static void IsDefined<T>(T value, string argumentName)
-            where T : Enum
-        {
-            if (!Enum.IsDefined(typeof(T), value))
-            {
-                throw new ArgumentOutOfRangeException(argumentName);
-            }
-        }
-        
-        public static void IsNotNull<T>(T argument, string argumentName)
-        {
-            if (argument is null)
-            {
-                throw new ArgumentNullException(argumentName);
-            }
-        }
-    }
-}