code: public void writeHeader()
                      throws ObjectManagerException
      {
          final String methodName = "writeHeader";
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.entry(this,
                          cclass,
                          methodName);
  
          try {
              java.io.FileOutputStream headerOutputStream = new java.io.FileOutputStream(storeDirectoryName
                                                                                         + java.io.File.separator
                                                                                         + headerIdentifier);
              java.io.DataOutputStream dataOutputStream = new java.io.DataOutputStream(headerOutputStream);
              java.io.FileDescriptor fileDescriptor = headerOutputStream.getFD();
              dataOutputStream.writeInt(version);
              dataOutputStream.writeLong(objectStoreIdentifier);
              dataOutputStream.writeLong(sequenceNumber);
              dataOutputStream.flush();
              headerOutputStream.flush();
              fileDescriptor.sync(); // Force buffered records to disk.
              headerOutputStream.close();
  
          } catch (java.io.IOException exception) {
              // No FFDC Code Needed.
              ObjectManager.ffdc.processException(this, cclass, methodName, exception, "1:706:1.17");
  
              if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
                  trace.exit(this,
                             cclass,
                             methodName,
                             new Object[] { exception });
              throw new PermanentIOException(this,
                                             exception);
          } // catch java.io.IOException.
  
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.exit(this,
                         cclass,
                         methodName);
      }
docs: Write header information for disk in the file headerIdentifier
  and force it to disk.
  
  @throws ObjectManagerException