code: public String[] getIdentifiers()
  	{
  		final PerSessionInfo[] infos;
  		synchronized (sessions)
  		{
  			infos = (PerSessionInfo[]) sessions.values().toArray(new PerSessionInfo[sessions.size()]);
  		}
  		int count = 0;
  		for (int i = 0; i < infos.length; ++i)
  		{
  			if (infos[i] != null && infos[i].identifier != null)
  			{
  				++count;
  			}
  		}
  		if (count > 0)
  		{
  			final String[] result = new String[count];
  			int index = 0;
  			for (int i = 0; i < infos.length; ++i)
  			{
  				if (infos[i] != null && infos[i].identifier != null)
  				{
  					result[index++] = infos[i].identifier;
  				}
  			}
  			return result;
  		} else
  		{
  			return null;
  		}
  	}
docs: /*
  @see IScriptBreakpoint#getIdentifiers()