HADOOP-18715. Add debug log for getting details of tokenKindMap (#5608). Contributed by Pralabh Kumar.

Signed-off-by: Ayush Saxena <ayushsaxena@apache.org>

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/Token.java

@@ -136,6 +136,7 @@ public class Token<T extends TokenIdentifier> implements Writable {
         while (tokenIdentifiers.hasNext()) {
           try {
             TokenIdentifier id = tokenIdentifiers.next();
+            LOG.debug("Added {}:{} into tokenKindMap", id.getKind(), id.getClass());
             tokenKindMap.put(id.getKind(), id.getClass());
           } catch (ServiceConfigurationError | LinkageError e) {
             // failure to load a token implementation