Explicitly import Lock

Author: smowton

java/ql/test/ext/TopJdkApis/TopJdkApisTest.java

@@ -37,6 +37,7 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.Lock;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;