code: protected synchronized void clear()
                      throws ObjectManagerException
      {
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.entry(this, cclass
                          , "clear"
                              );
  
          super.clear();
  
          managedObjectsOnDisk = new java.util.HashSet();
          managedObjectsToWrite = new ConcurrentHashMap(concurrency);
          tokensToDelete = new ConcurrentHashMap(concurrency);
  
          deleteDirectory(storeDirectoryName);
  
          // Make the directory to write the objects to.
          java.io.File storeDirectory = new java.io.File(storeDirectoryName);
          if (!(storeDirectory.isDirectory())) {
              storeDirectory.mkdirs();
          } // if (!(storeDirectory.isDirectory())).
  
          // Sequence numbers 0-200 are reserved.    
          sequenceNumber = initialSequenceNumber;
          writeHeader();
  
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.exit(this, cclass
                         , "clear"
                              );
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.ws.objectManager.ObjectStore#clear()