import sun.security.util.HostnameChecker;

public class T {
   public static void main(String[] argv) throws Exception {
HostnameChecker hc = HostnameChecker.getInstance(HostnameChecker.TYPE_LDAP);
   }
}

$ jdeps -jdkinternals T.class

Exception in thread "main" java.lang.NullPointerException
at java.util.Objects.requireNonNull(java.base/Objects.java:221)
at java.util.stream.Collectors.lambda$uniqKeysMapAccumulator$1(java.base/Collectors.java:176)
at java.util.stream.ReduceOps$3ReducingSink.accept(java.base/ReduceOps.java:169)
at java.util.stream.DistinctOps$1$2.accept(java.base/DistinctOps.java:175)
at java.util.HashMap$KeySpliterator.forEachRemaining(java.base/HashMap.java:1600)
at java.util.stream.ReferencePipeline$Head.forEach(java.base/ReferencePipeline.java:591)
at java.util.stream.ReferencePipeline$7$1.accept(java.base/ReferencePipeline.java:272)
at java.util.stream.ReferencePipeline$3$1.accept(java.base/ReferencePipeline.java:195)
at java.util.HashMap$KeySpliterator.forEachRemaining(java.base/HashMap.java:1600)
at java.util.stream.AbstractPipeline.copyInto(java.base/AbstractPipeline.java:484)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(java.base/AbstractPipeline.java:474)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(java.base/ReduceOps.java:913)
at java.util.stream.AbstractPipeline.evaluate(java.base/AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.collect(java.base/ReferencePipeline.java:511)
at com.sun.tools.jdeps.JdepsTask.analyzeDeps(jdk.jdeps/JdepsTask.java:602)
at com.sun.tools.jdeps.JdepsTask.run(jdk.jdeps/JdepsTask.java:536)
at com.sun.tools.jdeps.JdepsTask.run(jdk.jdeps/JdepsTask.java:483)
at com.sun.tools.jdeps.Main.main(jdk.jdeps/Main.java:48)