Allow contains to match an empty iterable

hamcrest/src/main/java/org/hamcrest/collection/IsIterableContainingInOrder.java

@@ -57,9 +57,6 @@ private static class MatchSeries<F> {
 
         public MatchSeries(List<Matcher<? super F>> matchers, Description mismatchDescription) {
             this.mismatchDescription = mismatchDescription;
-            if (matchers.isEmpty()) {
-                throw new IllegalArgumentException("Should specify at least one expected element");
-            }
             this.matchers = matchers;
         }
 

hamcrest/src/test/java/org/hamcrest/collection/IsIterableContainingInOrderTest.java

@@ -8,6 +8,7 @@
 import java.util.ArrayList;
 
 import static java.util.Arrays.asList;
+import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 import static org.hamcrest.test.MatcherAssertions.*;
 import static org.hamcrest.collection.IsIterableContainingInOrder.contains;
@@ -24,6 +25,31 @@ protected Matcher<?> createMatcher() {
         return contains(1, 2);
     }
 
+    @Test
+    public void testMatchingEmptyIterableWithNoExpectedItems() {
+        assertMatches(contains(new String[0]), emptyList());
+    }
+
+    @Test
+    public void testMatchingEmptyIterableWithNoExpectedMatchers() {
+        assertMatches(contains(new Matcher<?>[0]), emptyList());
+    }
+
+    @Test
+    public void testMatchingEmptyIterableWithEmptyMatcherList() {
+        assertMatches(contains(emptyList()), emptyList());
+    }
+
+    @Test
+    public void testDoesNotMatchNonEmptyIterableWithNoExpectedItems() {
+        assertMismatchDescription("not matched: <1>", contains(new Integer[0]), singletonList(1));
+    }
+
+    @Test
+    public void testHasAReadableDescriptionWithNoExpectedItems() {
+        assertDescription("iterable containing []", contains(new Integer[0]));
+    }
+
     @Test
     public void testMatchingSingleItemIterable() throws Exception {
         assertMatches("Single item iterable", contains(1), singletonList(1));