Remove empty lines and unused using statements

src/ImageSharp/Formats/Png/IPngDecoderOptions.cs

@@ -1,11 +1,7 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
-using System;
-using System.Collections.Generic;
-using System.IO;
 using System.Text;
-using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Formats.Png
 {
@@ -24,4 +20,4 @@ namespace SixLabors.ImageSharp.Formats.Png
         /// </summary>
         Encoding TextEncoding { get; }
     }
-}
+}

src/ImageSharp/Formats/Png/IPngEncoderOptions.cs

@@ -45,4 +45,4 @@ namespace SixLabors.ImageSharp.Formats.Png
         /// </summary>
         bool WriteGamma { get; }
     }
-}
+}

src/ImageSharp/Formats/Png/ImageExtensions.cs

@@ -37,4 +37,4 @@ namespace SixLabors.ImageSharp
             where TPixel : struct, IPixel<TPixel>
             => source.Save(stream, encoder ?? source.GetConfiguration().ImageFormatsManager.FindEncoder(ImageFormats.Png));
     }
-}
+}

src/ImageSharp/Formats/Png/PngChunk.cs

@@ -54,4 +54,4 @@ namespace SixLabors.ImageSharp.Formats.Png
             this.Type == PngChunkType.Data ||
             this.Type == PngChunkType.End;
     }
-}
+}

src/ImageSharp/Formats/Png/PngChunkType.cs

@@ -57,4 +57,4 @@ namespace SixLabors.ImageSharp.Formats.Png
         /// </summary>
         Physical = 0x70485973U // pHYs
     }
-}
+}

src/ImageSharp/Formats/Png/PngDecoder.cs

@@ -60,4 +60,4 @@ namespace SixLabors.ImageSharp.Formats.Png
             return decoder.Identify(stream);
         }
     }
-}
+}

src/ImageSharp/Formats/Png/PngDecoderCore.cs

@@ -1353,4 +1353,4 @@ namespace SixLabors.ImageSharp.Formats.Png
             this.scanline = temp;
         }
     }
-}
+}

src/ImageSharp/Formats/Png/Zlib/Adler32.cs

@@ -78,10 +78,7 @@ namespace SixLabors.ImageSharp.Formats.Png.Zlib
         public long Value
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get
-            {
-                return this.checksum;
-            }
+            get => this.checksum;
         }
 
         /// <inheritdoc/>

src/ImageSharp/Formats/Png/Zlib/IChecksum.cs

@@ -17,10 +17,7 @@ namespace SixLabors.ImageSharp.Formats.Png.Zlib
         /// <summary>
         /// Gets the data checksum computed so far.
         /// </summary>
-        long Value
-        {
-            get;
-        }
+        long Value { get; }
 
         /// <summary>
         /// Resets the data checksum as if no update was ever called.