Add guard for deviation -> Infinity

src/main/java/com/ethlo/time/statistics/ThroughputPerformanceStatistics.java

@@ -87,6 +87,10 @@ public Double getStandardDeviation()
     {
         final IndexedCollection<Long> list = collectionStatistics.getList();
         final int count = list.size();
+        if (count == 0)
+        {
+            return null;
+        }
         final double average = getAverage();
         BigDecimal sd = BigDecimal.valueOf(0);
         for (long l : list)

src/main/java/com/ethlo/util/LongList.java

@@ -93,7 +93,7 @@ public void set(final int index, final Long l)
     @Override
     public Iterator<Long> iterator()
     {
-        return new Iterator<Long>()
+        return new Iterator<>()
         {
             private int idx = 0;
 
@@ -143,7 +143,7 @@ public void sort()
     @Override
     public Stream<Long> stream()
     {
-        final Iterable<Long> iterable = LongList.this::iterator;
+        final Iterable<Long> iterable = LongList.this;
         return StreamSupport.stream(iterable.spliterator(), false);
     }
 }

src/test/java/com/ethlo/time/statistics/ThroughputPerformanceStatisticsTest.java

@@ -0,0 +1,25 @@
+package com.ethlo.time.statistics;
+
+import com.ethlo.util.IndexedCollection;
+import com.ethlo.util.IndexedCollectionStatistics;
+
+import com.ethlo.util.LongList;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Duration;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ThroughputPerformanceStatisticsTest
+{
+
+    @Test
+    void getStandardDeviation()
+    {
+        final IndexedCollection<Long> list = new LongList(1000);
+        list.add(123);
+        final ThroughputPerformanceStatistics stats = new ThroughputPerformanceStatistics(new IndexedCollectionStatistics(list), 5, Duration.ofMillis(456));
+        stats.getStandardDeviation();
+    }
+}