[hotfix][test] Fix some code styles in StreamSourceOperatorWatermarks…

…Test and StreamSourceOperatorLatencyMetricsTest

flink-streaming-java/src/test/java/org/apache/flink/streaming/runtime/operators/StreamSourceOperatorLatencyMetricsTest.java

@@ -68,9 +68,8 @@ public class StreamSourceOperatorLatencyMetricsTest extends TestLogger {
 	 */
 	@Test
 	public void testLatencyMarkEmissionDisabled() throws Exception {
-		testLatencyMarkEmission(0, (operator, timeProvider) -> {
-			setupSourceOperator(operator, new ExecutionConfig(), MockEnvironment.builder().build(), timeProvider);
-		});
+		testLatencyMarkEmission(0,
+			(operator, timeProvider) -> setupSourceOperator(operator, new ExecutionConfig(), MockEnvironment.builder().build(), timeProvider));
 	}
 
 	/**
@@ -170,7 +169,7 @@ private void testLatencyMarkEmission(int numberLatencyMarkers, OperatorSetupOper
 			operator.getContainingTask(),
 			StreamTask.createRecordWriters(operator.getOperatorConfig(), new MockEnvironmentBuilder().build()));
 		try {
-			operator.run(new Object(), mock(StreamStatusMaintainer.class), new CollectorOutput<Long>(output), operatorChain);
+			operator.run(new Object(), mock(StreamStatusMaintainer.class), new CollectorOutput<>(output), operatorChain);
 			operator.close();
 		} finally {
 			operatorChain.releaseOutputs();
@@ -207,6 +206,7 @@ private void testLatencyMarkEmission(int numberLatencyMarkers, OperatorSetupOper
 
 	// ------------------------------------------------------------------------
 
+	@SuppressWarnings("unchecked")
 	private static <T> void setupSourceOperator(
 			StreamSource<T, ?> operator,
 			ExecutionConfig executionConfig,

flink-streaming-java/src/test/java/org/apache/flink/streaming/runtime/operators/StreamSourceOperatorWatermarksTest.java

@@ -161,13 +161,13 @@ public void testAutomaticWatermarkContext() throws Exception {
 			processingTimeService.setCurrentTime(i);
 		}
 
-		assertTrue(output.size() == 9);
+		assertEquals(9, output.size());
 
 		long nextWatermark = 0;
 		for (StreamElement el : output) {
 			nextWatermark += watermarkInterval;
 			Watermark wm = (Watermark) el;
-			assertTrue(wm.getTimestamp() == nextWatermark);
+			assertEquals(wm.getTimestamp(), nextWatermark);
 		}
 	}