Add test WeightedRandomSamplingTest.feedAlternative

src/test/java/gr/james/sampling/WeightedRandomSamplingTest.java

@@ -5,9 +5,7 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Random;
+import java.util.*;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
@@ -106,4 +104,27 @@ public void cornerWeights() {
         alg.sample();
     }
 
+    /**
+     * Equivalence between {@link WeightedRandomSampling#feed(Object)},
+     * {@link WeightedRandomSampling#feed(Iterator, Iterator)} and {@link WeightedRandomSampling#feed(Map)}.
+     */
+    @Test
+    public void feedAlternative() {
+        final WeightedRandomSampling<Integer> rs1 = impl.get();
+        final WeightedRandomSampling<Integer> rs2 = impl.get();
+        final WeightedRandomSampling<Integer> rs3 = impl.get();
+        final Map<Integer, Double> map = new HashMap<>();
+        for (int i = 1; i <= SAMPLE; i++) {
+            map.put(i, (double) i);
+            rs1.feed(i, (double) i);
+        }
+        rs3.feed(map.keySet().iterator(), map.values().iterator());
+        rs2.feed(map);
+        Assert.assertEquals(SAMPLE, rs1.sample().size());
+        Assert.assertEquals(SAMPLE, rs2.sample().size());
+        Assert.assertEquals(SAMPLE, rs3.sample().size());
+        Assert.assertTrue(rs1.sample().containsAll(rs2.sample()));
+        Assert.assertTrue(rs2.sample().containsAll(rs3.sample()));
+    }
+
 }