Refactored byte[] array in PngConstants type

src/ImageSharp/Common/Extensions/StreamExtensions.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
-using System.Buffers;
 using System.IO;
 using SixLabors.ImageSharp.Memory;
 

src/ImageSharp/Formats/Png/PngConstants.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
 using System.Collections.Generic;
 using System.Text;
 
@@ -37,9 +38,9 @@ namespace SixLabors.ImageSharp.Formats.Png
         public static readonly IEnumerable<string> FileExtensions = new[] { "png" };
 
         /// <summary>
-        /// The header bytes identifying a Png.
+        /// Gets the header bytes identifying a Png.
         /// </summary>
-        public static readonly byte[] HeaderBytes =
+        public static ReadOnlySpan<byte> HeaderBytes => new byte[]
         {
              0x89, // Set the high bit.
              0x50, // P

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -149,7 +149,7 @@ namespace SixLabors.ImageSharp.Formats.Png
             QuantizedFrame<TPixel> quantized = PngEncoderOptionsHelpers.CreateQuantizedFrame(this.options, image);
             this.bitDepth = PngEncoderOptionsHelpers.CalculateBitDepth(this.options, image, quantized);
 
-            stream.Write(PngConstants.HeaderBytes, 0, PngConstants.HeaderBytes.Length);
+            stream.Write(PngConstants.HeaderBytes);
 
             this.WriteHeaderChunk(stream);
             this.WritePaletteChunk(stream, quantized);