@Test
public void testMapStateReturnsEmptyMapByDefault() throws Exception {

	StreamingRuntimeContext context = new StreamingRuntimeContext(
			createMapPlainMockOp(),
			createMockEnvironment(),
			Collections.<String, Accumulator<?, ?>>emptyMap());
	MapStateDescriptor<Integer, String> descr = new MapStateDescriptor<>("name", Integer.class, String.class);
	MapState<Integer, String> state = context.getMapState(descr);
	Iterable<Map.Entry<Integer, String>> value = state.entries();
	assertNotNull(value);
	assertFalse(value.iterator().hasNext());
}