public static Object getVersion(Object[] fields,
    EntityPersister persister) 
{
		if ( !persister.isVersioned() ) {
			return null;
		}
		return fields[ persister.getVersionProperty() ];
}

Extract the optimisitc locking value out of the entity state snapshot.

 public static Object increment(Object version,
    VersionType versionType,
    SessionImplementor session) 
{
		Object next = versionType.next( version, session );
		if ( log.isTraceEnabled() ) {
			log.trace(
					"Incrementing: " +
					versionType.toLoggableString( version, session.getFactory() ) +
					" to " +
					versionType.toLoggableString( next, session.getFactory() )
			);
		}
		return next;
}

Generate the next increment in the optimisitc locking value according the VersionType contract for the version property.

 public static boolean isVersionIncrementRequired(int[] dirtyProperties,
    boolean hasDirtyCollections,
    boolean[] propertyVersionability) 
{
		if ( hasDirtyCollections ) {
			return true;
		}
		for ( int i = 0; i <  dirtyProperties.length; i++ ) {
			if ( propertyVersionability[ dirtyProperties[i] ] ) {
				return true;
			}
		}
	    return false;
}

Do we need to increment the version number, given the dirty properties?

 public static boolean seedVersion(Object[] fields,
    int versionProperty,
    VersionType versionType,
    SessionImplementor session) 
{
		Object initialVersion = fields[versionProperty];
		if (
			initialVersion==null ||
			// This next bit is to allow for both unsaved-value="negative"
			// and for "older" behavior where version number did not get
			// seeded if it was already set in the object
			// TODO: shift it into unsaved-value strategy
			( (initialVersion instanceof Number) && ( (Number) initialVersion ).longValue()< 0 )
		) {
			fields[versionProperty] = seed( versionType, session );
			return true;
		}
		else {
			if ( log.isTraceEnabled() ) {
				log.trace( "using initial version: " + initialVersion );
			}
			return false;
		}
}

Create an initial optimisitc locking value according the VersionType contract for the version property if required and inject it into the snapshot state.

 public static  void setVersion(Object[] fields,
    Object version,
    EntityPersister persister) 
{
		if ( !persister.isVersioned() ) {
			return;
		}
		fields[ persister.getVersionProperty() ] = version;
}

Inject the optimisitc locking value into the entity state snapshot.