Simplify the code.

Author: dlemstra

src/Magick.NET/Statistics/ChannelPerceptualHash.cs

@@ -46,9 +46,10 @@ public double HuPhash(ColorSpace colorSpace, int index)
     {
         Throw.IfOutOfRange(nameof(index), index, 7);
 
-        var huPhashList = GetHuPhashListByColorSpace(colorSpace);
-        if (huPhashList is null)
+        if (!_huPhashes.TryGetValue(colorSpace, out var huPhashList))
+        {
             throw new ArgumentException("Invalid colorspace specified.", nameof(colorSpace));
+        }
 
         return huPhashList[index];
     }
@@ -101,16 +102,6 @@ private static double PowerOfTen(int power)
             _ => 10.0,
         };
 
-    private HuPhashList? GetHuPhashListByColorSpace(ColorSpace colorSpace)
-    {
-        if (_huPhashes.TryGetValue(colorSpace, out var huPhashList))
-        {
-            return huPhashList;
-        }
-
-        return null;
-    }
-
     private void ParseHash(ColorSpace[] colorSpaces, string hash)
     {
         _hash = hash;

src/Magick.NET/Statistics/PerceptualHash.cs

@@ -113,16 +113,10 @@ internal static void DisposeList(IntPtr list)
             NativePerceptualHash.DisposeList(list);
     }
 
-    private static ChannelPerceptualHash? CreateChannelPerceptualHash(IMagickImage image, ColorSpace[] colorSpaces, IntPtr list, PixelChannel channel)
-    {
-        var instance = NativePerceptualHash.GetInstance(image, list, channel);
-        return new ChannelPerceptualHash(channel, colorSpaces, instance);
-    }
-
     private void AddChannel(IMagickImage image, ColorSpace[] colorSpaces, IntPtr list, PixelChannel channel)
     {
-        var instance = CreateChannelPerceptualHash(image, colorSpaces, list, channel);
-        if (instance is not null)
-            _channels.Add(instance.Channel, instance);
+        var nativeInstance = NativePerceptualHash.GetInstance(image, list, channel);
+        var instance = new ChannelPerceptualHash(channel, colorSpaces, nativeInstance);
+        _channels.Add(instance.Channel, instance);
     }
 }