if ((null != usage) && (0 < usage.length()))
if ((null == usage) || (0 >= usage.length())) return (retval);  if ((null != persistedSource) && persistedSource.hasUsage(usage)) retval.add(persistedSource);  if ((null != sigAppSource) && sigAppSource.hasUsage(usage)) retval.add(sigAppSource);  for (Iterator srcs = signetSources.iterator(); srcs.hasNext(); )
	public Vector getSourcesByUsage(String usage)	{		Vector retval = new Vector();		if ((null != usage) && (0 < usage.length()))		{			for (Iterator srcs = signetSources.iterator(); srcs.hasNext();)			{				SignetSource src = (SignetSource)srcs.next();				if (src.hasUsage(usage))					retval.add(src);			}		}		return (retval);	}