[CodeFactor] Apply fixes to commit 0606491

lib/filters/sak/tests/Sak.Tests.cs

@@ -386,7 +386,7 @@ public sealed class SakTests
         var output = new double[size];
         for (int i = 0; i < size; i++)
         {
-            src[i] = 100.0 + i * 0.01;
+            src[i] = 100.0 + (i * 0.01);
         }
 
         // Should not throw StackOverflowException

lib/filters/sak/tests/Sak.Validation.Tests.cs

@@ -83,7 +83,7 @@ public sealed class SakValidationTests
         double c0 = alpha * alpha / 4.0;
 
         double x0 = 10.0, x1 = 20.0, x2 = 30.0;
-        double expectedY = c0 * (x0 + 2.0 * x1 + x2);   // pure FIR formula
+        double expectedY = c0 * (x0 + (2.0 * x1) + x2);   // pure FIR formula
 
         var sak = new Sak("Smooth", period: period);
         var now = DateTime.UtcNow;